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1. AUTHOR’S NOTE:

Eye: One of the most vital organs of human body that makes a person to see the beautiful

world. Lots of people are suffering from treatable eye disease in every part of the world

mainly in developing countries. Also many more are there who don’t have enough money for

the assessment of eye problems. The condition is pathetic in developing countries. Due to

poverty in the developing countries and high cost of diagnostic, these people are unable to get

their eye test done which finally result in loss of vision. Measuring someone for an eyeglass

prescription usually requires bulky diagnostic machines or high-tech laser scanners that

can cost thousands of dollars. This means that in the developing world, vision correction is

often an unattainable luxury for literally hundreds of millions of people. A team of

researchers at the MIT1 media lab has unveiled a system for prescribing eyeglasses that

requires nothing more than a Smartphone and a $1 plastic lens attachment. The NETRA2 is

thus a major assessment tools for people who can’t afford costly diagnostic test and are not

easily reachable. The cost effectiveness and easiness in handling makes it most viable

equipment in the diagnosis of the eye pathology.

Note: 1.MIT- Massachusetts Institute Of Technology

2. NETRA- Near Eye Tool for Refractive Assessment

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2. ABSTRACT

The human eye is one of the precious parts of our body. Eye care is an area with a

particularly high number of untreated patients.    Worldwide, it is estimated that at least 38

million people are blind and that an additional 110 million have severely impaired vision. In

all, about 150 million people are visually disabled in the world today, and the number is

steadily increasing because of population growth and aging. Overall, the data show that more

than 90% of all blind people live in developing countries and that more than two-thirds (over

half a billion )of all blindness is avoidable (either preventable or curable). Thus, trend

assessment points to a doubling of world blindness by the year 2020 unless more aggressive

intervention is undertaken. People worldwide suffer from different type of preventable eye

impairment. Current diagnostic system are large ,expensive ,disconnected and difficult to

operate .As a result ,many people in developing nations go without eye examination and

remain unaware that they have treatable eye condition. The technology NETRA exploits

mobile phone as scientific instrument to provide accessible health diagnostics to undeserved

areas of world. NETRA is a very easy diagnostics technique for the patient suffering from

treatable eye disease .this small portable solution allows for anyone, anywhere to get an exam

done. Hence it will play a very important role in achieving the vision 2020

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3. INTRODUCTION.

NETRA- A Possible paradigm shift in eye healthcare.

Hundreds of millions of people worldwide are suffering from treatable medical illness and

conditions-especially in developing regions. High cost and low accessibility of care –

including diagnostics- are the leading barriers of treatment. .

Eye care is an area with a particularly high number of untreated: over half a billion people

worldwide suffers from preventable eye impairment. Uncorrected refractive errors (i.e. Near

sightedness, farsightedness and astigmatism), Pres-byopia (age related eye condition) and

cataract (cloudiness in the eye) result in lost productivity, lost independence, illiteracy and

improvishment on a massive scale.

According to WHO statistics:

A total of 285 million people are visually impaired worldwide. 39 million are blind

and 246million have low vision.

About 90% of the world’s visually impaired live in developing countries.

Globally, uncorrected refractive errors are the main cause of visual impairment;

cataracts remain the leading cause of blindness in middle- and low-income countries.

80% of all visual impairment can be avoided or cured.

NETRA – a cheap device that enables checking of eyes using a Smartphone!

It is a portable and inexpensive solution for estimating refractive errors in the human eye.

Like a thermometer, Eye NETRA aim to empower hundreds of millions in their homes

through patient centric ecosystem that starts with diagnosis and awareness and end with

options for quality care. Eye NETRA is a very small, cheap device (that costs less than Rs.

100) that can be clipped on to a regular Smartphone and which can be used to detect vision

problems including detecting their lens prescription, astigmatism, and even cataract. Since it

is so cheap, and portable, it can be used in villages all over the world. This cell phone based

solution significantly reduces the cost of the device and makes it appropriate for self-

evaluation, while still providing comparable data.

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Fig 1: NETRA in Samsung smart phone

3.1 BRAIN BEHIND THE INVENTION:

This is the idea of Ramesh Raskar of the camera culture group at Massachusetts Institute

of Technology, who has devised a method of providing basic eye test using just a

Smartphone and a specially designed eyepiece. It could provide a home-based eye test for

millions of people who cannot easily access regular optometry services.

This Near Eye Tool for Refractive Assessment (NETRA) consists of a viewer that fits

over a cell phone’s screen combined with software running on the phone. To test a

person's eyesight, the phone displays an image – which may appear as a pair of parallel

lines, say – on the screen, which the eyepiece converts into a virtual 3d display.

3.2 EXISTING TECHNIQUES

Existing systems to diagnose refractive eye conditions include Snell’s charts (with a set of

trial lenses), auto-Refracto-meters, and wave front Aberro-meters.  The NETRA solution

offers some unique benefits over these existing techniques, which make it especially suited

for deployment in developing countries:

Cost: NETRA relies on innovative use of existing hardware (a cell-phone), and custom

software. It augment an existing cell-phone display with a device that costs as little as

$2. This is significantly cheaper than sophisticated techniques such as aberro-meters,

and even a set of trial lenses which costs $100 or more.

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Safety: Since the device does not use lasers, has no need for drugs, and includes no

moving parts, there are reduced concerns about danger in improper use, specialized

training, or damage in transit.

Speed: Conventional methods of diagnosis usually require two steps (step 1 objectively

measures the refraction error, and step 2 verifies it based on patient feedback). This

NETRA hybrid approach combines these in a single user-driven step to obtain a

measurement in less than 3 minutes.

Accuracy: Unlike the Snell’s chart, the NETRA system relies on a simple alignment

task rather than the patient's ability to discern blur. This gives comparable accuracy,

and a simpler user interaction task.

Mobility: Based on a cell-phone, the NETRA system easily fits in a backpack for

remote deployment.

Self-evaluation: The ease of use, cheap cost, and the inherent safety of the NETRA

system allows for (possibly at-home) self-evaluation

4. BRIEF TECHNICAL DESCRIPTION

The NETRA system uses the dual of a Shack-Hartman sensor, and replaces the laser with

simple user interaction. Today methods using the shack-Hartman sensor shine a laser into the

eye of the patient, and measure the reflected light with a wave front sensor. Hence they are

quite expensive, and require a trained professional operator.  A cell phone based solution

significantly reduces the cost of the device and makes it appropriate for self-evaluation, while

still providing comparable data.

5. NETRA TEST TECHNIQUE:

Using NETRA is quite simple. It doesn’t need any intensive training. Anyone can do the test.

The patient looks through a lens in the clip-on device at the cell phone's screen, using the

arrow keys on the phone's keypad to move sets of parallel green and red lines around until

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they overlap. This is done eight times for each eye and the software in the phone can

determine the prescription. The entire process takes no more than two minutes.

Fig: 2-Test Technique

6. ADVANTAGES.

Cheap : $2 only.

Quick : Less than 2 min test to deliver prescription.

Easily assessable: : Portable

No training : Operation manual very easy

Safety : No use of laser

Self evaluation

RESTRICTIONS.

Not suitable for illiterate people who can’t read the diagnosis.

Smart phone needed.

No suitable for infectious eye disease.

It is only for objective assessment of refractive diseases.

Not a replacement for optometrist.

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7. COMPARATIVE STUDY:

Technique Speed Accuracy Energy

require

ment

Mobilit

y

Train

ing

Equipment

requiremen

t

Cost

efficiency

Retinoscope Fast +/-.50 d

Depend

upon

accommoda

tion

Batteries Good High Retinoscope

-

$2000,+trial

lens

Economical

Eye chart Slow +/- 0.25d

but

dependent

on patient

reliability

_ Good HighTrial lens set and trial frame($1400), or phoropter ($1000), or variable focus specs ($600)

Economical

Auto

refraction

Fast Relies on

both

equipment

and patient

factors

Mains Low Basic Auto-

refractor

($15k)

Expensive

Portable

auto

refractionFast

Relies on

both

equipment

and patient

factors

Mains&

batteries

Good Basic Portable

auto-

refractor

($20k)

Expensive

NETRA Fast Relies on both equipment and patient factors  < 0.50d unless affected by

- Excelle

nt

Basic Plastic

piece ($2)

and a cell

phone

($300).

Economical

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accommodation

* Costs were extracted from the vision2020 report. Some cheaper options may exist - for

example, a set of trial lenses for $300. Simple reading charts can be expensive because they

must be used under optimal lighting conditions and need a set of trial lenses.

8. WORLDWIDE IMPACT

Fig: 3-NETRA Testing and Reach Area

9. AWARDS

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Innovation award

10. CONCLUSION: This device is going to prove a boon for eye care assessment .It will

bring the eye care self assessment to each and every hand which needs it.

10.1. EXECUTIVE SUMMERY

The NETRA is going to play one of the important tools for the diagnosis of the eye

assessment. The cost, accuracy and handling mode is a major factor in the success of this

equipment. It is equivalent to the thermometer for optometry. It is a boom for the developing

as well as poor countries where eye diagnosis is still costly and unreachable for the general

population. Also this will save a lot of time for the physician .At the same time it will be

pocket friendly for both the healthcare provider as well as patient. The use of NETRA

through the smart phones reveals its eco-friendly nature.

11. REFERENCE-

http://www.vision2020.org/main.cfm

Eyenetra.com/

Media.mit.edu/~pamplona/netra

Vitor f. Pamplona, ankit mohan, manuel m. Oliveira, ramesh raskar. 

Netra: interactive display for estimating refractive errors and focal range. 

Proc. Of siggraph 2010 (acm transactions on graphics 29, 4), 2010. 

Vitor f. Pamplona, ankit mohan, manuel m. Oliveira, ramesh raskar. 

Dual of shack-hartmann optometry using mobile phones. 

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Proc. Of frontiers in optics, optical society of america. Oct. 24, rochester, new york.

2010. 

Vision2020 report, holden2007cfm