a review of visual functions and their impact on driving...

A Review of Visual Functions and Their Impact on Driving Behavior

Chris A. Johnson, Ph.D., D.SC., FAAO Professor, Department of Ophthalmology and Visual Sciences

University of Iowa Hospitals and Clinics

It has often been reported that vision is an important component of operating a motor vehicle. However, which properties of vision are most important for safe and effective driving ? In this presentation I will provide a summary of what is currently known about the significance of specific visual performance factors on driving tasks. Visual Acuity – Visual acuity is the most common visual function that is tested for driver’s license applicants. Fine detail, such as traffic signs, road hazards highway markings and related information requires a best-corrected visual acuity of 20/40 or better (which is the requirement for many states). However, each state in the USA has variations (both eyes, the better eye, use of optical devices such as a bioptic telescope, etc). Many investigations have demonstrated that poor visual acuity is a risk factor for safe driving. Contrast Sensitivity – Several studies have indicated that contrast sensitivity is an important visual feature for safe driving, particularly for detection and identification of low contrast objects under impoverished visual conditions (rain, snow, fog, nighttime, etc.). Contrast sensitivity has become a topic of greater interest in driving studies recently, and there are now several rapid test procedures that are available for population based testing. Glare disability – Investigating the influence of glare on driving is a complicated task. There is glare disability and glare recovery. Some aspects of glare are related to road conditions and weather and some are due to lighting conditions and other oncoming vehicles. (Question: are the new high intensity headlights a good thing [for drivers] or a bad thing [a hazard for oncoming vehicles because of glare] ?). Glare can certainly disrupt safe driving abilities, and changes in a driver’s lens with increasing age produce greater problems with glare with older drivers. However, there is currently no consensus among experts as to what test procedure

is appropriate for assessing this property in drivers, and no standardized test is currently available for performing this test. Visual Fields – Early investigations found no relationship between visual field extent and driving performance (evaluated by accident and conviction records). However, these studies were performed with visual field test procedures that had not been validated and were known to have poor performance characteristics (low sensitivity and specificity and high false positive and false negative rates). A large population-based study of licensed drivers applying for renewal (using a clinically validated visual field screening procedure) found that a small percentage of these drivers had visual field abnormalities, that the prevalence was greater in older populations, and that there was no difference in accident and conviction records in drivers with normal visual function and those with visual field loss in only one eye. However, the accident and conviction rate was more than double this amount for drivers with visual field loss in both eyes. More recent studies have confirmed that visual field reductions are a risk factor for safe driving. Initial investigations reported that the visual field of the better eye was the primary determinant and that moderate to advanced loss was associated with driving problems. However, the latest investigations have found that even mild visual field losses are associated with driving problems, even if it is only in one eye. Stereoacuity - Although stereopsis has been examined as a potential visual function that may affect driving, there is no compelling evidence that it plays an important role. There are many individuals without stereopsis (amblyopia or “lazy eye” is present in more than 2% of the population, and these drivers are not worse than those with normal visual function). Stereopsis is a rather slow visual response that has its primary benefits for near work (less than 4 feet), so it would not be effective for high-speed activities requiring quick responses to distant objects. It should also be kept in mind that stereoacuity is not equivalent to depth perception – it is only one of many visual cues for determining depth. Color Vision – The literature indicates that color vision is important for being able to properly detect and recognize traffic signals, and the ability to recognize illuminated taillights from a distance at night. Approximately 8% of the male population has some form of congenital color vision deficiency, and only a small percentage of women have this condition (less than 0.1%). However, many eye diseases produce color vision problems. Devices that are reported to “correct” color vision loss have not been shown to be effective. However, driving

performance and related studies have demonstrated that it is only those individuals with moderate to sever color vision loss that have an impairment in their driving abilities (less than 2% of the population). The automotive industry has altered their color designations for tail lights (less red and more orange) to improve their design for individuals with red (protanope) color vision problems. Vernier Acuity – Vernier acuity, or the ability to align the position of adjacent objects, is one of the most sensitive and precise visual functions. It is useful for tasks for measurement (using a ruler or other measuring device) or for obtaining accurate readings from a dial or other indicator. However, it does not appear to be important for driving, and there are no known studies that have demonstrated that this is an important component of the driving task. Dark Adaptation, Night Vision – Dr. Fred Owens will present a summary of the role of vision for night driving and some of the complications that it creates. There are more accidents that occur at night, visibility is less at night than in the daytime, many drivers do not adjust their speed of driving for night conditions, and there is tremendous individual variability in night vision among drivers. Moreover, it is a challenge to design a test that could be rapidly administered to prospective drivers to test for night vision. Some eye diseases specifically reduce the ability to see at night, or result in greatly prolonged times to adapt from a light environment to darkness. Flicker and Motion (Temporal visual processing) – Although visual changes produced by flicker and motion are important factors related to driving (self-motion and motion of other objects), there is little that is currently known about these factors related to driving safety. Exceptions to this include the study of biological motion, time to collision, judging the relative speed of other vehicles, and spatial orientation related to motion influences. More work is needed in this area. Dynamic Visual Acuity – Because drivers are mostly moving when operating a motor vehicle and many outside objects are also in motion, the ability to identify fine detail under these conditions (dynamic visual acuity) is important. However, this is also a topic that has not received as much attention as other visual functions, partly because it is again a complicated issue with many variations, making it difficult to achieve a standardized, quantifiable approach.

Other Visual Functions – There are additional issues that are important for driving (visual search, “pop-out” phenomena, eye-hand coordination, multitasking, visual-auditory compatibility, etc.) that require additional exploration, as well as issues related to the use of one eye (monocular) or two (binocular), visual capabilities of individuals with differing levels of function between the two eyes, etc. Summary

Although there are many other factors related to the task of driving (e.g., decision making, cognition, attention, multitasking, etc.) there are many aspects of vision that are important for safe and effective driving abilities. Visual acuity, contrast sensitivity, glare, visual fields, color vision, night vision, motion perception and dynamic visual acuity are all important for being able to successfully perform the driving task.

References (a partial list)

1. Bohensy M, Charlton J, Odell M, Keeffe J. Implications of Vision Testing for Older

Licensing. Traffic Injury Prevention 2008; 9:304-313.

2. Vision Requirements for Driving Safety with Emphasis on Individual Assessment,

Report prepared for the International Council of Ophthalmology at the 30th World

Ophthalmology Congress, Sao Paulo, Brazil, February 2006.

3. Charman WN. Visual standards for driving. Ophthalmic Physiol Opt. 1985, 5: 211-220.

4. Charman WN. Vision and driving—a literature review and commentary. Ophthalmic

Physiol Opt. 1997, 17: 371-391.

5. Keltner JL, Johnson CA. Visual function and driving safety. Arch Ophthalmol, 1992,

110: 1697-1698.

6. Brinig MF, Wilkinson ME, Daly JM, Jogerst GJ, Stone EM. Vision standards for

licensing and driving. Optometry. 2007, 78: 439-445.

7. Casson EJ, Racette L. Vision standards for driving in Canada and the United States. A

review for the Canadian Ophthalmological Society. Can J Ophthalmol. 2000, 35: 192-

203.

8. Burg A. Visual acuity as measured by dynamic and static tests: a comparative

evaluation. J Appl Psychol, 1966, 50: 460-466.

9. Burg A. Lateral visual field as related to age and sex. J Appl Psychol, 1968, 52: 10-15.

10. Burg A. The relationship between vision test scores and driving record: General findings.

Report 67-24, Department of Engineering, University of California, Los Angeles, 1967.

11. Burg A. Vision test scores and driving record: Additional findings. Report 68-27,

Department of Engineering, University of California, Los Angeles, 1968.

12. Wood JM, Owens DA. Standard measures of visual acuity do not predict drivers’

recognition performance under day or night conditions. Optom Vis Sci, 2005, 82: 698-

705.

13. Evans DW, Ginsburg AP. Contrast sensitivity predicts age-related differences in

highway sign discriminability. Hum Factors, 1985, 27: 637-642.

14. Ginsburg AP. Contrast sensitivity and functional vision. Int Ophthalmol Clin. 2003, 43:

5-15.

15. Johnson CA, Keltner JL. Incidence of visual field loss in 20,000 eyes and its relationship

to driving performance. Arch Ophthalmol, 1983, 101: 371-375.

16. Owen VM, Crabb DP, White ET, Viswanathan AC, Garway-Heath DF, Hitchings RA.

Glaucoma and fitness to drive: using binocular visual fields to predict a milestone to

blindness. Invest Ophthalmol Vis Sci. 2008, 49: 2449-2455.

17. Hassan SE, Turano KA, Monuz B, Munro C, Roche KB, West SK. Cognitive and vision

loss affects the topography of the attentional visual field. Invest Ophthalmol Vis Sci.

2008, 49: 4672-4678.

18. McKean-Cowdin R, Varma R, Wu J, Hays RD, Azen SP, Los Angeles Latino Eye Study

Group. Severity of visual field loss and health-related quality of life. Am J Ophthalmol.

2007, 143: 1013-1023.

19. Haymes SA, LeBlanc RP, Nicolela MT, Chiasson LA, Chauhan BC. Risk of falls and

motor vehicle collisions in glaucoma. Invest Ophthalmol Vis Sci. 2007, 48: 1149-1155.

20. Racette L, Casson EJ. The impact of visual field loss on driving performance: evidence

from on-road driving assessments. Optom Vis Sci, 2005, 82: 668-674.

21. Bowers A, Peli E, Elgin J, McGwin G, Owsley C. On-road driving with moderate visual

field loss. Optom Vis Sci. 2005, 82: 657-667.

22. Petzold A, Plant GT. Central and paracentral visual field defects and driving abilities.

Ophthalmologica. 2005, 219: 191-201.

23. Szlyk JP, Mahler CL, Seiple W, Esward DP, Wilensky JT. Driving performance of

glaucoma patients correlates with peripheral visual field loss. J Glaucoma. 2005, 14:

145-150.

24. Crabb DP, Fitzke FW, Hitchings RA, Viswanathan AC. A practical approach to

measuring the visual field component of fitness to drive. Br J Ophthalmol. 2004, 88:

1191-1196.

25. Wood JM, Troutbeck R. Effect of restriction of the binocular visual field on driving

performance. Ophthalmic Physiol Opt. 1992, 12: 291-298.

26. McKnight AJ, Shinar D, Hilburn B. The visual and driving performance of monocular

and binocular heavy-duty truck drivers. Accid Anal Prev, 1991, 23: 225-237.

27. North RV. The relationship between the extent of visual field and driving performance –

a review. Ophthalmic Physiol Opt, 1985, 5: 205-210.

28. Novack TA, Banos JH, Alderson AL, Schneider JJ, Weed W, Blankenship J, Salisbury D.

UFOV performance and driving ability following traumatic brain injury. Brain Inj. 2006,

20: 455-461.

29. Myers RS, Ball KK, Kalina TD, Roth DL, Goode Kt. Relation of useful field of view

and other screening tests to on-road driving performance. Percept Mot Skills. 2000, 91:

279-290.

30. Crundall D, Underwood G, Chapman P. Driving experience and the functional field of

view. Perception. 1999, 28: 1075-1087.

31. Ball K, Owlsey C, Sloane ME, Roenker DL, Bruni JR. Visual attention problems as a

predictor of vehicle crashes in older drivers. Invest Ophthalmol Vis Sci. 1993, 34: 3110-

3123.

32. Okonkwo OC, Crowe M, Wasley VG, Ball K. Visual attention and self-regulation of

driving among older adults. Int Psychogeriatr. 2008, 20: 162-173.

33. Ball K, Owsley C. The useful field of view test: a new technique for evaluating age-

related declines in visual function. J Am Optom Assoc. 1993, 64: 71-79.

34. Dain SJ, Wood JM, Atcheson DA. Sunglasses, traffic signals, and color vision

deficiencies. Optom Vis Sci, 2009, 86: 296-305.

35. Atchison DA, Pedersen CA, Dain SJ, Wood JM. Traffic signal color recognition is a

problem for both protan and deutan color-vision deficients. Hum Factors, 2003, 45: 495-

503.

36. Matsumoto ER, Johnson CA, Post RB. Effect of X-Chrom lens wear on chromatic

discrimination and stereopsis in color-deficient observers. Am J Optom Physiol Opt.

1983, 60: 297-302.

37. O’Brien KA, Cole BL, Maddocks JD, Forbes AB. Color and defective color vision as

factors in the conspicuity of signs and signals. Hum Factors, 2002, 44: 665-675.

38. Cole BL. Protan color vision deficiency and road accidents. Clin Exp Optom. 2002, 85:

246-253.

39. Vingrys AJ. The case against protan drivers holding professional driving licenses. Clin

Exp Optom. 2002, 85: 46-48.

40. Uc EY, Rizzo M, Anserson SW, Dastrup E, Sparks JD, Dawson JD. Driving under low-

contrast visibility conditions in Parkinson disease. Neurology, 2009, 73: 1103-1110.

41. Ramulu PY, West SK, Munoz B, Jampel HD, Friedman DS. Driving cessation and

driving limitation in glaucoma: the Salisbury Eye Evaluation Project. Ophthalmology.

2009, 116: 1846-1853.

42. Keay L, Munoz B, Turano KA, Hassan SE, Munro CA, Duncan DD, Baldwin K, Jasti S,

Gower EW, West SK. Visual and cognitive deficits predict stopping or restricting

driving: the Salisbury Eye Evaluation Driving Study (SEEDS). Invest Ophthalmol Vis

Sci. 2009, 50: 107-113.

43. Marrington SA, Horswill MS, Wood JM. Thje effect of simulated cataracts on drivers’

hazard perception ability. Optom Vis Sci. 2008, 85: 1121-1127.

44. Kotecha A, Spratt A, Viswanathan A. Visual function and fitness to drive. Br MED

Bull. 2008, 87: 163-174.

45. Haymes SA, LeBlanc RP, Nicolela MT, Chiasson LA, Chauhan BC. Glaucoma and on-

road driving performance. Invest Ophthalmol Vis Sci. 2008, 49: 3035-3041.

46. Stav WB, Justiss MD, McCarthy DP, Mann WC, Lanford DN. Predictability of clinical

assessments for driving performance. J Safety Res. 2008, 39: 1-7.

47. Wood JM, Carberry TP. Bilateral cataract surgery and driving performance. BrJ

Ophthalmol. 2006, 90: 1277-1280.

48. Ballantyne B. Glaucopsia: an occupational ophthalmic hazard. Toxicol Rev. 2004, 23:

83-90.

49. Wood JM, Garth D, Grounds G, McKay P, Mulvahil A. Pupil dilatation does affect some

aspects of daytime driving performance. Br J Ophthalmol. 2003, 87: 1387-1390.

50. Wood JM. Age and visual impairment decrease driving performance as measured on a

closed-road circuit. Hum Factors. 2002, 44: 482-494.

51. Owsley C, McGwin G. Vision impairment and driving. Surv Ophthalmol. 1999, 43:

535-550.

52. Wilkinson ME. Driving with a vision impairment. Insight. 1998, 23: 48-52.

53. Wood JM, Troutbeck R. Effect of visual impairment on driving. Hum Factors. 1994, 36:

476-487.

54. Keltner JL, Johnson CA. Visual function and driving safety. Arch Ophthalmol. 1992,

110: 1697-1698.

55. Tyrrell RA, Wood JM, Chaparro A, Carberry TP, Chu BS, Marszalek RP. Seeing

pedestrians at night: visual clutter does not mask biological motion. Accid Anal Prev.

2009, 41: 506-512.

56. Owens DA, Wood JM, Owens JM. Effects of age and illumination on night driving: a

road test. Hum Factors, 2007, 49: 1115-1131.

57. Brabyn JA, Schneck ME, Lott LA, Haegerstrom-Portnoy G. Night driving self-

restriction: vision function and gender differences. Optom Vis Sci, 2005, 82: 755-764.

58. Andre J, Owens DA. The twilight envelope: a user-centered approach to describing

roadway illumination at night. Hum Factors, 2001, 43: 620-630.

59. Leibowitz HW, Owens DA, Tyrrell RA. The assured clear distance ahead rule:

implications for nighttime traffic safety and the law. Accid Anal Prev. 1998, 30: 93-99.

60. Vivoda JM, Eby DW, St Louis RM, Kostynuik LP. Cellular phone use while driving at

night. Traffic Inj Prev. 2008, 9: 37-41.

61. Chisholm SL, Caird JK, Lockhart J. The effects of practice with MP3 players on driving

performance. Accid Anal Prev. 2008, 40: 704-713.

62. Caird JK, Willness CR, Steel P, Scialfa C. A meta-analysis of the effects of cell phones

on driver performance. Accid Anal Prev. 2008, 40: 1282-1293.

63. Maples WC, DeRosier W, Hoenes R, Bendure R, Moore S. The effects of cell phone use

on peripheral vision. Optometry. 2008, 79: 36-42.

64. Bowers AR, Apfelbaum DH, Peli E. Bioptic telescopes meet the needs of drivers with

moderate visual acuity loss. Invest Ophthalmol Vis Sci. 2005, 46: 66-74.

65. Bailey IL. Bioptic Telescopes. Arch Ophthalmol. 1985, 103: 13-14.

66. Fonda G. Bioptic telescopic spectacle is a hazard for operating a motor vehicle. Arch

Ophthalmol. 1983, 101: 1907-1908.

67. Ross LA, Anstey KJ, Kiely KM, Windsor TD, Byles JE, Luszcz MA, Mitchell P. Older

drivers in Australia: trends in driving status and cognitive and visual impairment. J Am

Geriatr Soc. 2009, 57: 1868-1873.

68. Dawson JD, Anderson SW, UC EY, Dastrup E, Rizzo M. Predictors of driving safety in

early Alzheimer disease. Neurology. 2009, 72: 521-527.

69. Subzwari S, Desapriya E, Babul-Wellar S, Pike I, Turcotte K, Rajabali F, Kinney J.

Vision screening of older drivers for preventing road traffic injuries and fatalities.

Cochrane Database Syst Rev. 2009, Jan 21: CD006252.

70. Wood JM, Anstey KJ, Kerr GK, Lacherez PF, Lord S. A multidomain approach for

predicting older driver safety under in-traffic road conditions. J Am Geriatr Soc. 2008,

56: 986-993.

71. Rubin GS, Ng ES, Bandeen-Roche K, Keyl PM, Freeman EE, West SK. A prospective,

population-based study for the role of visual impairment in motor vehicle crashes among

older drivers: the SEE study. Invest Ophthalmol Vis Sci. 2007, 48: 1483-1491.

72. Freeman EE, Munoz, Turano KA, West SK. Measures of visual function and time to

driving cessation in older adults. Optom Vis Sci. 2005, 82: 765-773.

73. Chaparro A, Wood JM, Carberry. Effects of age and auditory and visual dual tasks on

closed-road driving performance. Optom Vis Sci. 2005, 82: m747-754.

74. Wood JM. Aging, driving and vision. Clin Exp Optom. 2002, 85: 214-220.

75. Owsley C. Vision and driving in the elderly. Optom Vis Sci. 1994, 71: 727-735.

76. Keltner JL, Johnson CA. Visual function, driving safety and the elderly.

Ophthalmology. 1987, 94: 1180-1188.

77. McGregor LN, Chaparro A. Visual difficulties reported by low-vision and nonimpaired

older adult drivers. Hum Factors. 2005, 47: 469-478.

78. Tijtgat P, Mazyn L, DeLaey C, Lenoir M. The contribution of stereo vision to the control

of braking. Accid Anal Prev. 2008, 40: 719-724.

79. Bauer A, Dietz K, Kolling G, Hart W, Schiefer U. The relevance of stereopsis for

motorists: a pilot study. Grafes Arch Clin Exp Ophthalmol. 2001, 239: 400-406.

80. Fleck R, Kolling GH. Two new stereotests for long distance: examination of stereopsis

with regard to the permission of driving. Ger J Ophthalmol. 1996, 5: 53-59.

81. Johnson CA. Vision requirements for drivers license examiners. Optom Vis Sci. 2005,

82: 779-789.

82. Higgins KE, Wood JM. Predicting components of closed road driving performance from

vision tests. Optom Vis Sci. 2005, 82: 647-656.

83. Mallon K, Wood JM. Occupational therapy assessment of open-road driving

performance: validity of directed and self-directed navigational instructional components.

Am J Occup Therapy. 2004, 58: 279-286.

84. Trobe JD. Test of divided visual attention predicts automobile crashes among older

adults. Arch Ophthalmol. 1998, 116: 665.

85. Hills BL. Vision, visibility and perception in driving. Perception. 1980, 9: 183-216.

86. Classe, JG. Clinicolegal Aspects of Practice. Southern Journal of Optometry. 1986 IV, I

January.

87. Foubister V. To Tell or Not—Physician’s Dilemma about Patient’s who Drive Impaired.

American Medical News, 1999 November, 22-29, 8-9.

88. Grabowski DC, Campbell CM, Morrisey, MA. Elderly licensure laws and motor vehicle

fatalities. J Am Med Assn. 2004, 291: 2840-2846.

89. Levy DT, Vernick JS, Howard KA. Relationship between driver’s license renewal

policies and fatal crashes involving drivers 70 years or older. Am Med Assn. 1995, 274:

1026-1030.

90. McGwin G, Sarrels SA, Griffin R, Owsley C, Rue LW. The Impact of a Vision

Screening Law on Older Driver Fatality Rates, Arch Ophthalmol 2008; 126 (No.11):

1544-1547.

91. Molnar FJ, Marshall SC, Man-Son-Hing M, Wilson KG, Byszewski AM, Stiell I.

Acceptability and concurrent validity of measures to predict older driver involvement in

motor vehicle crashes: An Emergency Department pilot case-control study, Accident

Analysis and Prevention 2007; 39:1056-1063

92. Owsley C, McGwin G. Vision impairment and driving, Surv Ophthalmol, 1999, 43: 535-

550.

93. Shipp MD. Potential human and economic cost-savings attributable to vision testing

policies for driver license renewal, 1989-1991 Optom Vis Sci. 1998; 75 (2): 103-118.

94. Subzwari S, Desapriya E, Desapriya E, Badul-Wellar S, Pike I, Turcotte K, Rajabali F,

Kinney J. Vision screening of older drivers for preventing road traffic injuries and

fatalities (Review), Cochrane Database of Systematic Reviews 2009, Issue 1. Art.

No.:CD006252. DOI: 10.1002/14651858.CD006252.pubs.

Vision and Driving: The United States

Chris A. Johnson, PhD, Mark E. Wilkinson, OD

Abstract: Minimal visual standards for obtaining drivinglicensure in the United States principally use 2 measures:visual acuity and visual field. Although research studieshave established a correlation between performance onthese measures and safe driving, the correlations areweak andmostly retrospective. These measures remain inplace in screening centers largely because they (espe-cially visual acuity) are practical. A newer test of visualattention, called the useful field of view, may be morepredictive of safe driving than the traditional measures,but it has not been widely applied in licensing bureaus.

Journal of Neuro-Ophthalmology 2010;30:170–176doi: 10.1097/WNO.0b013e3181df30d4! 2010 by North American Neuro-Ophthalmology Society

D riving is a complex multifaceted activity in whichvisual performance is a critical feature. Research

projects utilizing more detailed and thorough approacheshave produced new insights into the role of vision duringthe driving task and the use of technological advances toimprove the driving experience for individuals with visualimpairments. We review the research directed toward visionand driving with an emphasis on visual acuity, contrastsensitivity, color vision, and visual fields. Although atten-tion, visual search, decision making, and other cognitivefunctions are also clearly involved with driving perfor-mance, these components are reviewed elsewhere (1,2).

While it is a fundamental responsibility of licensingbodies to identify drivers with impairments that place themat an unacceptable risk for crashes, the decisions they makeabout licensing must be legally and morally defensible andmust not unfairly restrict the mobility of disabled or agingdrivers. It is important, therefore, that the licensing criteriafor visual fitness be based on scientific evidence establishingtheir effectiveness and predictive value for unsafe drivingperformance, particularly for older drivers (1). Surprisingly,there is no rigorous evidence to support the hypothesis that

vision screening leads to a reduction in motor vehiclecrashes involving older drivers or that a specific cutoff valuefor vision performance improves safety (2). This seemingconundrum is probably resolved by acknowledging thatdriving safety depends less on what the driver sees thanon how quickly, adequately, and accurately he responds towhat is seen (2).

Many review articles have evaluated the relationshipsamong driving performance, vision, decision-making be-havior, risk-benefit analysis, and related factors (3–9); butfew have incorporated these issues within the context ofvisual performance, driving demands, and visual and cog-nitive impairment questions that arise during the courseof an eye examination. Following a brief review of visualfactors affecting driving, we discuss the issues directlypertinent to eye care providers.

HISTORICAL PERSPECTIVE

The foundations of research on vision and driving can betraced back to the Transactions of the Section onOphthalmology of the American Medical Association’sSeventy Sixth Annual Session in Atlantic City, New Jersey,on May 25–29, 1925 (10). The Committee on VisualStandards for Drivers of Motor Vehicles recommended thatdriver license applicants demonstrate a visual acuity of atleast 20/50 in one eye and at least 20/100 in the fellow eye,with or without glasses. Applicants with visual acuity worsethan 20/100 in the poorer eye could be qualified to drivea motor vehicle by a special board under certain circum-stances. Diplopia would disqualify an applicant from ob-taining a license to operate a motor vehicle.

The next formal report concerning vision standards fordriving appeared on October 16, 1937 in the OrganizationSection of the Journal of the American Medical Association(Vision Standards for Licensure to Operate a Motor Vehicle)(11), which indicated that the 1925 recommendations fora board of physical licensure in each county had proved tobe impracticable and had therefore not been embodied intolaw or practice. The report also indicated that standards ofgood vision necessary for efficient operation of a motor

Section Editors: Grant T. Liu, MDRandy H. Kardon, MD, PhD

Department of Ophthalmology and Visual Sciences, University ofIowa Hospitals and Clinics, Iowa City, Iowa.

170 Johnson and Wilkinson: J Neuro-Ophthalmol 2010; 30: 170-176

State-of-the-Art Review

Copyright © North American Neuro-ophthalmology Society.Unauthorized reproduction of this article is prohibited.

vehicle could not be arbitrarily fixed because the problem ofsafety also depended on factors such as the driver’s naturalaptitude, experience, and general mental and physical fit-ness. The lack of good vision might be compensated for by ahigh degree of efficiency in aptitude, experience, and mentaland physical fitness. The report modified the vision stan-dard for driving licensure to 20/40 or better in one eye (withor without glasses) and 20/100 or better in the fellow eye(with or without glasses). It recommended a horizontalextent of the visual field of at least 45" to both sides of thepoint of fixation; a binocular single vision; and the ability todistinguish red, green, and yellow. A limited driving licensecould be obtained with a visual acuity of at least 20/65 in thebetter eye, a field of vision extending at least 125" hori-zontally in one eye, and the absence of diplopia. Personalqualities that could compensate for minor defects of visionwould have to be highly rated in those to whom a limitedlicense was to be issued.

The 1937 report was followed by investigations per-formed by Burg (12–15) in landmark studies published inthe 1960s. These studies evaluated a large population ofCalifornia drivers on an extensive battery of vision, reactiontime, and decision-making tests. This work served as a basisfor establishing vision requirements for a driving license,although many questions arose concerning the individualsselected for inclusion in the study, the methodology used insome of the test procedures, and the analysis proceduresused in evaluation of the data. Burg’s work (12–15) wasa retrospective study of the association of vision and cognitiveproperties with driving accidents and convictions; no vali-dation or prospective evaluations were performed. Subsequentstudies of vision and driving have explored the influence ofvisual impairment on driving, the use of devices to accom-modate disabilities, and cognitive and decision-making as-pects of driving (1,2,7,16–93). Using driving simulators,population-based studies, closed road tracks, and retrospectivereviews of driving accidents and convictions, they have pro-vided more sophisticated information on visual performanceand driving behavior, as described in a later section of thisarticle. The factors most often considered are visual acuity,contrast sensitivity, visual fields, and color vision.

Despite much research on these topics, there remainsignificant differences in vision requirements for drivinglicensure throughout the world. In fact, each of the 50 statesin the United States has its own requirements.

VISUAL FUNCTIONS AND OTHER FACTORSRELATED TO DRIVING

Most studies indicate that visual acuity, contrast sensitivity,visual fields, and color vision have the strongest relationshipto driving performance (12–43). We will provide a sum-mary of results from these investigations, and direct theinterested reader to the more comprehensive reviews(6–11). In the past, most research was directed at

establishing the relationship between vision and drivingamong individuals with normal vision. Only recently, therehave been efforts toward evaluating the driving abilities ofindividuals with vision impairments (1,44–55).

Visual Acuity

Visual acuity is the most universal vision requirement forobtaining a driving license. Tests of visual acuity can beadministered rapidly with a standardized test procedure bypersonnel with minimal visual testing skills. It is ac-knowledged as critical for interpreting traffic signs anddetecting road hazards. In the United States, most juris-dictions require an unaided or best-corrected visual acuity of20/40 in the better eye (7). Most of the signage and otherroadside information have been designed to be read byindividuals with 20/40 or better visual acuity who are op-erating a motor vehicle at or below the speed limit.

A number of studies have evaluated the consequences ofdriving with reduced visual acuity produced by cataract orother ocular and neurologic diseases or by artificially de-grading vision by means of lenses or translucent devices inpersons with normal visual acuity (46,49,50,53–55).Thesestudies have mostly been performed retrospectively by re-viewing visual acuity status and traffic accidents and con-victions in the general population, the elderly, the young,and those with physical or mental impairments. Prospectivestudies have measured driving performance on a closed roadtrack or in a driving simulator (1,46–55). Reductions invisual acuity produce impairments in certain aspects ofdriving related to specific driving tasks, such as recognitionof road signs, road hazards, highway markings, and objectsentering the roadway (29).

Contrast Sensitivity

Evans and Ginsburg (17) and Ginsburg (18) have reportedthat contrast sensitivity is an important factor in being ableto distinguish the legibility of highway signs and otherproperties of functional vision that are associated withdriving, such as recognition of road signs, hazards, trafficsignals, and indicator markers. In bad weather and in nightdriving, highway signs, road hazards, animals, and pedes-trians have low contrast. For this reason, many studies haveincorporated the detection and discrimination of low-contrast objects as part of their driving research (44).

Night Vision

At night, highways and intersections are not as well de-lineated. The span of useable vision is smaller due tononuniform lighting of the highway and the short distancefor which the headlights of a vehicle can illuminate theroadway. Paradoxically, drivers tend to maintain nighttimedriving speeds at nearly the same level as daytime drivingspeeds (56–60). Accidents are more than twice as frequentat night (56–60). Regrettably, there has been very littleuseful research on night time driving.


Johnson and Wilkinson: J Neuro-Ophthalmol 2010; 30: 170-176 171


Visual Fields and Attention

Early investigations did not find a meaningful relationshipbetween peripheral vision and accident and convictionreports (13). Among the many factors responsible for thislack of a relationship are the low prevalence of visual fieldloss in the general population; self-restriction of driving byindividuals with ocular or neurologic disorders; the use ofperipheral vision test equipment with high false-positiveand false-negative rates; and the lack of reproducibility,confirmation, and validation of test findings (19).

But with a visual field instrument of known performancecharacteristics, a study (19) finally found that drivers withsignificant visual field loss in both eyes had more than twiceas many accidents and convictions as drivers with normalvisual fields or loss in only one eye. Subsequently, manystudies reported a relationship between visual field loss anddriving performance (20–31). When the binocular visualfield was reduced to 50"–60" in diameter, impairmentsin driving performance were noted (19,20,22). However,more recent investigations have found that even relativelyminor amounts of visual field loss are related to deficits indriving performance (22,23).

The devices that perform clinical visual field testing relyon the subject’s ability to detect a single stimulus super-imposed on a uniform background. Because driving is muchmore complex, investigators (32–37) have developed a testknown as the useful field of view (UFOV), which combinesperipheral target detection with measurements of reactiontime, the ability to perform multiple tasks (includingsimultaneous central and peripheral target recognition), andthe ability to localize targets and distinguish one from another(see Anticipated Future Developments). The intent of theUFOV test is to provide a more powerful surrogate of thevisual and cognitive tasks encountered during driving. Studies(32–37) have verified that this test is useful in identifying taskperformance difficulties associated with driving impairments.

Color Vision

The role of color vision in safe driving is complex becausedeficient color vision can be congenital or acquired, stableor progressive, partial or complete, and affect primarily red(protan), green (deutan), blue (tritan), or all color sensitivevisual mechanisms. Moreover, color is not the only visualattribute used to distinguish a critical visual target. In-dividuals with red (protan) deficiencies have greater diffi-culty seeing red traffic signals and automobile tail lights atnight, thereby producing a higher risk of traffic accidents(39–41). Individuals with protan (red) and deutan (green)deficits have greater difficulty recognizing traffic signalcolors and the conspicuity of signs and signals (39,41–43).Many sunglass manufacturers do not adhere to therecommended specifications for tint colorations and pro-duce spectacles that create significant difficulties for color-deficient observers (38).

Although color vision performance is not a componentof the standard for obtaining a standard driving license inthe United States, it is a component for obtaining a com-mercial vehicle driving license. To obtain a US commercialdriving license, the driver must be able to distinguish trafficcontrol signals and devices showing red, green, and ambercolors. Some European countries use it as a component forobtaining a standard driving license.

Other Factors

Even if visual modalities are intact, their integration withauditory, memory, and other sensory information can be anespecially difficult task for youthful, elderly, or neurologi-cally impaired individuals. This lack of integration may leadto an increase in vehicular accidents (61–64). For example,studies have shown that cellular telephone use during drivingdisrupts sensory tasks and driving performance (61–64).

The effect of instruction, rehabilitation, and the use ofassistive devices on driving performance has been controversial(11,24,25,30,44,48–50,54,55,58,61–64,70,71,77,83,92).For example, the use of bioptic telescopes by drivers who arevisually impaired has been advocated by some vision spe-cialists but considered hazardous by others (65–67). Amongthose who favor them, the assumption is that these deviceswill be used according to the instructions provided by themanufacturer and the eye care specialist prescribing them.Although there is evidence that drivers use them mostly tospot signs (65–67), they will experience inattention blind-ness as they switch their fixation from the carrier lens to thebioptic. A talking global position system might be a saferoption for older drivers with visual impairments. Adaptivecruise control, lane alert warnings, and self-parking cars mayalso be a boon to drivers with visual impairments, butstudies are yet to be forthcoming on these issues.

Aging

Driving accidents and convictions are higher in youths andin the elderly (2,68–77), but there are large individualdifferences. No consistent factors, such as cognitive decisionmaking, attention, driving experience, or training programs,have been identified.

Stereopsis

Investigations of stereopsis and driving performance(78–80) have failed to disclose any important impact ofreduced function.

TRADITIONAL VISION TESTING

Visual Acuity

Visual acuity has traditionally been evaluated by readinga series of progressively smaller letters or symbols on a chart.For the most part, this procedure has been shown to beeffective in providing a quick, accurate, and easily




administered test that is relevant to the driving task. Themethodology for visual acuity assessment has been stan-dardized, and it is unlikely that meaningful improvementsto the procedure will be achieved through more extensiveresearch. This procedure therefore appears to be adequatefor vision screening for a driving license.

Contrast Sensitivity

Contrast sensitivity is measured in many different ways withno consensus as to which method is most appropriate fordriving. At the present time, contrast sensitivity is regardedas an important visual factor for driving, but the use ofa specific screening procedure has not yet been achieved.Moreover, a determination of the amount and quality ofinformation that it can provide beyond visual acuity needsfurther investigation.

Visual Fields

Visual field testing is time consuming. Rapid screeningtechniques such as the Humphrey matrix have been able togenerate a screening procedure that takes 20–30 seconds pereye in those without defects and 60 seconds per eye in thosewith defects. However, this procedure only evaluates thecentral 30" radius of the visual field, thereby limiting itsutility for evaluation of the full visual field. There area number of other rapid screening techniques, but they havenot been subjected to a rigorous investigation in this setting.

CURRENT ISSUES IN VISION AND DRIVING

As of 2004, all drivers licensed in Florida who are 80 yearsand older are required to meet a minimum visual acuityrequirement to renew their driver licenses. They are re-quired to pass a letter acuity test of 20/40 or better at thetime of renewal or provide a certificate from a licensedallopathic physician, osteopathic physician, or optometristdemonstrating that they have passed a vision test within thepast year. When comparing prelaw and postlaw periods, theall-cause fatality rate, adjusted for age, race, and sex, amongall aged drivers increased by 6% but decreased by 17%among drivers aged 80 years and older (88). Prior researchdone by Shipp and others (89–93) had suggested that stateswith mandated visual acuity tests have lower motor vehiclecollision fatality rates among older individuals. Grabowskiet al (88) found that in-person license renewal was relatedto a significantly lower fatality rate among the most elderlydrivers. More stringent state licensure policies related tovision or road tests and more frequent license renewal cycleswere not independently associated with additional benefits.After controlling for middle-aged daytime driver deaths, theonly policy related to significantly lower driving fatalityrates was the requirement for in-person license renewal.License renewal included a visual acuity test or a referral toa medical practitioner for further medical screening in somestates.

PHYSICIAN REPORTING OF VISUALLYIMPAIRED DRIVERS

Physicians working in jurisdictions where reporting a pa-tient who is at high risk for a motor vehicle accident is notmandatory still have a moral and ethical obligation to reportin order to preserve patient and public safety (83,84). TheDuty to Warn is a legal rationale intended to providea means of protecting the patient from an unreasonable riskof harm. Failure to warn patients of conditions that createa risk of injury will be upheld as a cause of action against eyecare providers when it can be shown that the failure to warnis the proximate cause of an injury. Patients may argue thatthey had insufficient warning of their impairment, andbecause of their impairment, their operation of a motorvehicle or other machinery resulted in an injury. Thus,patients whose vision no longer legally qualifies them tooperate a motor vehicle should be warned not to drive anda notation to this effect should be entered into the patient’srecord (86,87).

In 1999, the American Medical Association (AMA)House of Delegates approved a recommendation that callson doctors to breach patient confidentiality for the good ofboth the patient and the society. The AMA stated that it isdesirable and ethical for physicians to notify the Departmentof Motor Vehicles or an equivalent agency if an impairedpatient fails to restrict driving appropriately (87).

Mandatory reporting concerns include the question ofrelative benefit, and different states have varying legalopinions about mandatory reporting. If mandatory report-ing detours someone from confiding or getting necessarycare, because he or she fears losing driving privileges, thenreporting statutes could backfire, creating more hazardousdrivers. There has been a long-standing controversy as towhether driving is a privilege or a right. Driving is subject toreasonable regulations in the interest of public safety andwelfare. The suspension or revocation of an operator’s li-cense is not intended as a punishment to the driver but isdesigned solely for the protection of the public. The AMAPhysician’s Plan for Older Drivers’ Safety (2003) (3) statesthat every physician (we would include optometrists) shouldassess risk factors for older patients who drive (4). For thoseindividuals at risk of unsafe driving, the practitioner shouldrecommend a formal assessment of vision, cognition, andmotor skills and also refer for a road test when appropriate.

ANTICIPATED FUTURE DEVELOPMENTS

The UFOV is a specialized visual field test that has beendeveloped for evaluation of driving and peripheral vision(32–37). It differs from other tests of peripheral visualfunction by incorporating measures of reaction time,stimulus localization, simultaneous central and peripheralvisual tasks (multitasking), target identification, and com-plex decision making. The UFOV provides a means of




evaluating the driver’s ability to perform multiple tasksaccurately and quickly to simulate the driving task. Studiesperformed with this procedure indicate that it correlateswith driving performance (32–37). This procedure is nowbeing used by a greater number of health care professionalswho are concerned with driving and other mobility tasks;but careful research has been limited to only a few labo-ratories, and there is a strong need for additional work.Currently, the UFOV test is considered too costly and timeconsuming to be used for screening on a widespread pop-ulation basis.

The rapid increase in vision and driving research hasgenerated a number of questions as to the impact on safedriving of multisensory integration of information andassimilation of sensory, cognitive, decision making, andattentional properties. Also, important are validation oflaboratory studies when applied to population imple-mentation and public policy, rehabilitation and trainingregimens to compensate for disabilities, evidence-basedguidelines, and legal liabilities. No single group is capable ofaddressing all relevant issues, and a consolidation of thisinformation through meta-analysis or overviews cansometimes be difficult. The Cochrane Report (69) providesa comprehensive objective assessment of current findingsand directed efforts primarily toward identifying the im-portance of vision screening for prediction of traffic acci-dents and fatalities. The authors concluded that 1) nostudies to date met their inclusion criteria (randomizedcontrolled trial before and after studies comparing visionscreening to nonscreening of drivers aged 55 and older), 2)there is insufficient evidence to assess the effect of visionscreening on elderly drivers, and 3) valid and reliable visionscreening tools need to be developed to properly evaluatethis topic in a more thorough fashion.

CONCLUSIONS

Our knowledge concerning the relationship between visualperformance and driving has increased in recent years.Highly competent laboratories and research teams haveconducted a number of research studies and evaluations.However, policy decisions, accuracy and efficiency of testinglarge populations, interpretation of test results, legal ram-ifications, and risk assessment currently determine the re-quirements for a driving license. A procedure that is highlyeffective in a research project has not yet been found ap-plicable for general use in screening drivers.

The United Kingdom and other countries have adopteda uniform vision standard for driving licensure. The UnitedStates has not, with the result that there are 50 standards ofvisual performance needed to obtain a driving license. Thereare also meaningful variations in the licensing requirementsamong different countries in Europe, Asia, and SouthAmerica. We propose that the United States adopt a na-tional vision standard for driving personal vehicles similar to

that of the United Kingdom. Such a standard would placethe responsibility on drivers rather than eye care providers toknow if they are visually qualified to drive, and enforcementwould be conducted by departments of motor vehicles andlaw enforcement agencies. This approach would also re-move concerns about mandatory reporting of impaireddrivers by health care professionals. It would be an appli-cation of the principle used in qualifying for a commercialdriving license.

REFERENCES1. Keay L, Munoz B, Turano KA, Hassan SE, Munro CA,

Duncan DD, Baldwin K, Jasti S, Gower EW, West SK. Visualand cognitive deficits predict stopping or restrictingdriving: the Salisbury Eye Evaluation Driving Study(SEEDS). Invest Ophthalmol Vis Sci. 2009;50:107–113.

2. Ross LA, Anstey KJ, Kiely KM, Windsor TD, Byles JE,Luszcz MA, Mitchell P. Older drivers in Australia: trends indriving status and cognitive and visual impairment. J AmGeriatr Soc. 2009;57:1868–1873.

3. Bohensky M, Charlton J, Odell M, Keeffe J. Implications ofvision testing for older licensing. Traffic Inj Prev. 2008;9:304–313.

4. Colenbrander A, De Laey JJ. Vision Requirements for DrivingSafety with Emphasis on Individual Assessment. Reportprepared for the International Council of Ophthalmology atthe 30th World Ophthalmology Congress. Sao Paulo, Brazil,February 2006. Available at: http://www.icoph.org/pdf/visionfordriving.pdf. Accessed March 22, 2010.

5. Charman WN. Visual standards for driving. OphthalmicPhysiol Opt. 1985;5:211–220.

6. Charman WN. Vision and driving—a literature review andcommentary. Ophthalmic Physiol Opt. 1997;17:371–391.

7. Keltner JL, Johnson CA. Visual function and driving safety.Arch Ophthalmol. 1992;110:1697–1698.

8. Brinig MF, Wilkinson ME, Daly JM, Jogerst GJ, Stone EM.Vision standards for licensing and driving. Optometry. 2007;78:439–445.

9. Casson EJ, Racette L. Vision standards for driving in Canadaand the United States. A review for the CanadianOphthalmological Society. Can J Ophthalmol. 2000;35:192–203.

10. Behrens C, Finnoff WC, Gradle HS, Posey WC. Report ofcommittee on visual standards for drivers of motor vehicles.Trans Sect Ophthalmol Am Med Assoc. 1925;76:361–362.

11. Black NM, Gradle HS, Snell AC. Visual standards forlicensure to operate motor vehicles: preliminary report ofspecial committee at Atlantic City session. J Am MedAssoc. 1937;109:61B–63B.

12. Burg A. Visual acuity as measured by dynamic and statictests: a comparative evaluation. J Appl Psychol. 1966;50:460–466.

13. Burg A. Lateral visual field as related to age and sex. J ApplPsychol. 1968;52:10–15.

14. Burg A. The Relationship Between Vision Test Scoresand Driving Record: General Findings. Report 67–24.Los Angeles, CA: Department of Engineering, Universityof California; 1967.

15. Burg A. Vision Test Scores and Driving Record: AdditionalFindings. Report 68–27. Los Angeles: Department ofEngineering, University of California; 1968.

16. Wood JM, Owens DA. Standard measures of visual acuity donot predict drivers’ recognition performance under day ornight conditions. Optom Vis Sci. 2005;82:698–705.

17. Evans DW, Ginsburg AP. Contrast sensitivity predictsage-related differences in highway sign discriminability.Hum Factors. 1985;27:637–642.

18. Ginsburg AP. Contrast sensitivity and functional vision. IntOphthalmol Clin. 2003;43:5–15.




19. Johnson CA, Keltner JL. Incidence of visual field loss in20,000 eyes and its relationship to driving performance.Arch Ophthalmol. 1983;101:371–375.

20. Owen VM, Crabb DP, White ET, Viswanathan AC, Garway-Heath DF, Hitchings RA. Glaucoma and fitness to drive:using binocular visual fields to predict a milestone toblindness. Invest Ophthalmol Vis Sci. 2008;49:2449–2455.

21. Hassan SE, Turano KA, Monuz B, Munro C, Roche KB,West SK. Cognitive and vision loss affects the topographyof the attentional visual field. Invest Ophthalmol Vis Sci.2008;49:4672–4678.

22. McKean-Cowdin R, Varma R, Wu J, Hays RD, Azen SP; LosAngeles Latino Eye Study Group. Severity of visual field lossand health-related quality of life. Am J Ophthalmol. 2007;143:1013–1023.

23. Haymes SA, LeBlanc RP, Nicolela MT, Chiasson LA,Chauhan BC. Risk of falls and motor vehicle collisions inglaucoma. Invest Ophthalmol Vis Sci. 2007;48:1149–1155.

24. Racette L, Casson EJ. The impact of visual field loss ondriving performance: evidence from on-road drivingassessments. Optom Vis Sci. 2005;82:668–674.

25. Bowers A, Peli E, Elgin J, McGwin G, Owsley C. On-roaddriving with moderate visual field loss. Optom Vis Sci. 2005;82:657–667.

26. Petzold A, Plant GT. Central and paracentral visual fielddefects and driving abilities. Ophthalmologica. 2005;219:191–201.

27. Szlyk JP, Mahler CL, Seiple W, Edward DP, Wilensky JT.Driving performance of glaucoma patients correlates withperipheral visual field loss. J Glaucoma. 2005;14:145–150.

28. Crabb DP, Fitzke FW, Hitchings RA, Viswanathan AC.A practical approach to measuring the visual fieldcomponent of fitness to drive. Br J Ophthalmol. 2004;88:1191–1196.

29. Wood JM, Troutbeck R. Effect of restriction of the binocularvisual field on driving performance. Ophthalmic Physiol Opt.1992;12:291–298.

30. McKnight AJ, Shinar D, Hilburn B. The visual and drivingperformance of monocular and binocular heavy-duty truckdrivers. Accid Anal Prev. 1991;23:225–237.

31. North RV. The relationship between the extent of visual fieldand driving performance – a review. Ophthalmic Physiol Opt.1985;5:205–210.

32. Novack TA, Banos JH, Alderson AL, Schneider JJ, Weed W,Blankenship J, Salisbury D. UFOV performance and drivingability following traumatic brain injury. Brain Inj. 2006;20:455–461.

33. Myers RS, Ball KK, Kalina TD, Roth DL, Goode Kt. Relationof useful field of view and other screening tests to on-roaddriving performance. Percept Mot Skills. 2000;91:279–290.

34. Crundall D, Underwood G, Chapman P. Driving experienceand the functional field of view. Perception. 1999;28:1075–1087.

35. Ball K, Owlsey C, Sloane ME, Roenker DL, Bruni JR. Visualattention problems as a predictor of vehicle crashes in olderdrivers. Invest Ophthalmol Vis Sci. 1993;34:3110–3123.

36. Okonkwo OC, Crowe M, Wasley VG, Ball K. Visual attentionand self-regulation of driving among older adults. IntPsychogeriatr. 2008;20:162–173.

37. Ball K, Owsley C. The useful field of view test: a newtechnique for evaluating age-related declines in visualfunction. J Am Optom Assoc. 1993;64:71–79.

38. Dain SJ,Wood JM, Atchison DA. Sunglasses, traffic signals,and color vision deficiencies. Optom Vis Sci. 2009;86:e296–e305.

39. Atchison DA, Pedersen CA, Dain SJ, Wood JM. Traffic signalcolor recognition is a problem for both protan and deutancolor-vision deficients. Hum Factors. 2003;45:495–503.

40. Matsumoto ER, Johnson CA, Post RB. Effect of X-Chromlens wear on chromatic discrimination and stereopsis in

color-deficient observers. Am J Optom Physiol Opt. 1983;60:297–302.

41. O’Brien KA, Cole BL, Maddocks JD, Forbes AB. Color anddefective color vision as factors in the conspicuity of signsand signals. Hum Factors. 2002;44:665–675.

42. Cole BL. Protan color vision deficiency and road accidents.Clin Exp Optom. 2002;85:246–253.

43. Vingrys AJ. The case against protan drivers holdingprofessional driving licenses. Clin Exp Optom. 2002;85:46–48.

44. Uc EY, Rizzo M, Anderson SW, Dastrup E, Sparks JD,Dawson JD. Driving under low-contrast visibility conditionsin Parkinson disease. Neurology. 2009;73:1103–1110.

45. Ramulu PY, West SK, Munoz B, Jampel HD, Friedman DS.Driving cessation and driving limitation in glaucoma: theSalisbury Eye Evaluation Project. Ophthalmology. 2009;116:1846–1853.

46. Marrington SA, Horswill MS, Wood JM. The effect ofsimulated cataracts on drivers’ hazard perception ability.Optom Vis Sci. 2008;85:1121–1127.

47. Kotecha A, Spratt A, Viswanathan A. Visual function andfitness to drive. Br Med Bull. 2008;87:163–174.

48. Haymes SA, LeBlanc RP, Nicolela MT, Chiasson LA,CHauhan BC. Glaucoma and on-road driving performance.Invest Ophthalmol Vis Sci. 2008;49:3035–3041.

49. Stav WB, Justiss MD, McCarthy DP, Mann WC, Lanford DN.Predictability of clinical assessments for drivingperformance. J Safety Res. 2008;39:1–7.

50. Wood JM, Carberry TP. Bilateral cataract surgery anddriving performance. Br J Ophthalmol. 2006;90:1277–1280.

51. Ballantyne B. Glaucopsia: an occupational ophthalmichazard. Toxicol Rev. 2004;23:83–90.

52. Wood JM, Garth D, Grounds G, McKay P, Mulvahil A. Pupildilatation does affect some aspects of daytime drivingperformance. Br J Ophthalmol. 2003;87:1387–1390.

53. Wood JM. Age and visual impairment decrease drivingperformance as measured on a closed-road circuit. HumFactors. 2002;44:482–494.

54. Wilkinson ME. Driving with a vision impairment. Insight.1998;23:48–52.

55. Wood JM, Troutbeck R. Effect of visual impairment ondriving. Hum Factors. 1994;36:476–487.

56. Tyrrell RA, Wood JM, Chaparro A, Carberry TP, Chu BS,Marszalek RP. Seeing pedestrians at night: visual clutterdoes not mask biological motion. Accid Anal Prev. 2009;41:506–512.

57. Owens DA, Wood JM, Owens JM. Effects of age andillumination on night driving: a road test. Hum Factors.2007;49:1115–1131.

58. Brabyn JA, Schneck ME, Lott LA, Haegerstrom-Portnoy G.Night driving self-restriction: vision function and genderdifferences. Optom Vis Sci. 2005;82:755–764.

59. Andre J, Owens DA. The twilight envelope: a user-centeredapproach to describing roadway illumination at night. HumFactors. 2001;43:620–630.

60. Leibowitz HW, Owens DA, Tyrrell RA. The assured cleardistance ahead rule: implications for nighttime traffic safetyand the law. Accid Anal Prev. 1998;30:93–99.

61. Vivoda JM, Eby DW, St. Louis RM, Kostynuik LP. Cellularphone use while driving at night. Traffic Inj Prev. 2008;9:37–41.

62. Chisholm SL, Caird JK, Lockhart J. The effects of practicewith MP3 players on driving performance. Accid Anal Prev.2008;40:704–713.

63. Caird JK,Willness CR, Steel P, Scialfa C. A meta-analysis ofthe effects of cell phones on driver performance. Accid AnalPrev. 2008;40:1282–1293.

64. Maples WC, DeRosier W, Hoenes R, Bendure R, Moore S.The effects of cell phone use on peripheral vision.Optometry. 2008;79:36–42.




65. Bowers AR, Apfelbaum DH, Peli E. Bioptic telescopes meetthe needs of drivers with moderate visual acuity loss. InvestOphthalmol Vis Sci. 2005;46:66–74.

66. Bailey IL. Bioptic telescopes. Arch Ophthalmol. 1985;103:13–14.

67. Fonda G. Bioptic telescopic spectacle is a hazard foroperating a motor vehicle. Arch Ophthalmol. 1983;101:1907–1908.

68. Dawson JD, Anderson SW, Uc Ey, Dastrup E, Rizzo M.Predictors of driving safety in early Alzheimer disease.Neurology. 2009;72:521–527.

69. Subzwari S, Desapriya E, Babul-Wellar S, Pike I, Turcotte K,Rajabali F, Kinney J. Vision screening of older drivers forpreventing road traffic injuries and fatalities. CochraneDatabase Syst Rev. 2009;CD006252.

70. Wood JM, Anstey KJ, Kerr GK, Lacherez PF, Lord S. Amultidomain approach for predicting older driver safetyunder in-traffic road conditions. J Am Geriatr Soc. 2008;56:986–993.

71. Rubin GS, Ng ES, Bandeen-Roche K, Keyl PM, Freeman EE,West SK. A prospective, population-based study for the roleof visual impairment in motor vehicle crashes among olderdrivers: the SEE study. Invest Ophthalmol Vis Sci. 2007;48:1483–1491.

72. Freeman EE, Munoz, Turano KA, West SK. Measures ofvisual function and time to driving cessation in older adults.Optom Vis Sci. 2005;82:765–773.

73. Chaparro A, Wood JM, Carberry T. Effects of age andauditory and visual dual tasks on closed-road drivingperformance. Optom Vis Sci. 2005;82:747–754.

74. Wood JM. Aging, driving and vision. Clin Exp Optom. 2002;85:214–220.

75. Owsley C. Vision and driving in the elderly. Optom Vis Sci.1994;71:727–735.

76. Keltner JL, Johnson CA. Visual function, driving safety andthe elderly. Ophthalmology. 1987;94:1180–1188.

77. McGregor LN, Chaparro A. Visual difficulties reported bylow-vision and nonimpaired older adult drivers. HumFactors. 2005;47:469–478.

78. Tijtgat P, Mazyn L, DeLaey C, Lenoir M. The contribution ofstereo vision to the control of braking. Accid Anal Prev.2008;40:719–724.

79. Bauer A, Dietz K, Kolling G, Hart W, Schiefer U. Therelevance of stereopsis for motorists: a pilot study. GrafesArch Clin Exp Ophthalmol. 2001;239:400–406.

80. Fleck R, Kolling GH. Two new stereotests for long distance:examination of stereopsis with regard to the permission ofdriving. Ger J Ophthalmol. 1996;5:53–59.

81. Johnson CA. Vision requirements for driver’s licenseexaminers. Optom Vis Sci. 2005;82:779–789.

82. Higgins KE, Wood JM. Predicting components of closedroad driving performance from vision tests. Optom Vis Sci.2005;82:647–656.

83. Mallon K, Wood JM. Occupational therapy assessment ofopen-road driving performance: validity of directed and self-directed navigational instructional components. Am JOccup Therapy. 2004;58:279–286.

84. Trobe JD. Test of divided visual attention predictsautomobile crashes among older adults. Arch Ophthalmol.1998;116:665.

85. Hills BL. Vision, visibility and perception in driving.Perception. 1980;9:183–216.

86. Classe, JG. Clinicolegal aspects of practice: liability forocular urgencies and emergencies. Southern JOptom.1986;4:51–58.

87. Foubister V. To tell or not—physician’s reports on patientsdriving impaired. American Medical News. November 22,1999:8.

88. Grabowski DC, Campbell CM, Morrisey, MA. Elderlylicensure laws and motor vehicle fatalities. JAMA. 2004;291:2840–2846.

89. Levy DT, Vernick JS, Howard KA. Relationship betweendriver’s license renewal policies and fatal crashes involvingdrivers 70 years or older. JAMA. 1995;274:1026–1030.

90. McGwin G Jr, Sarrels SA, Griffin R, Owsley C, Rue LW III. Theimpact of a vision screening law on older driver fatalityrates, Arch Ophthalmol. 2008;126:1544–1547.

91. Molnar FJ, Marshall SC, Man-Son-Hing M, Wilson KG,Byszewski AM, Stiell I. Acceptability and concurrentvalidity of measures to predict older driver involvement inmotor vehicle crashes: an Emergency Department pilotcase-control study. Accid Anal Prev. 2007;39:1056–1063.

92. Owsley C,McGwin G Jr. Vision impairment and driving, SurvOphthalmol. 1999;43:535–550.

93. Shipp MD. Potential human and economic cost-savingsattributable to vision testing policies for driver licenserenewal, 1989–1991 Optom Vis Sci. 1998;75:103–118.




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