the world through our senses presentation
DESCRIPTION
science form 2TRANSCRIPT
SENSE OF SIGHT & HEARING
The World Through Our Senses…
LIMITATION OF SIGHTOptical illusion
Blind spot
Not able to see too distant object
Not able to see too tiny
objects
Cannot see through opaque objects
Limitation of sight is also known as monocular vision and stereoscopic vision.
STEREOSCOPIC VISION:
OPTIC ILLUSION What we see not only depends on
our eyes, but also on our brain. Sometimes brain distorts images. This gives rise to optical illusion the image formed in the eyes is accurate but the brain plays a trick on us and makes the image mis lead.
THE BLIND SPOT When images fall on the blind spot,
they cannot be seen. This is because there are no photo receptors on it.
OPTICAL INSTRUMENTS
Optical instruments
used to overcome
the limitation of
sight
BINOCULAR
TELESCOPE
X-RAY
MICROSCOPE
HEARING1) The most common hearing
defects are the inability to detect sound and the difficulty of hearing with ease.
2) Deafness may caused by several factors:
- damage of the ossicles - damage of the eardrums - damage of the cochlea - damage of the auditory nerve
3) Bacterial or viral infections and high fever may lead to damage of the inner ear.
4) Long exposure to loud sound may increase the chance of becoming deaf.
5) Some of the hearing limitations can be corrected by using modern devices such as hearing aids which can be used to help people for hearing problem and surgery can be carried out to replace damaged ossicles and eardrums.
6) Other than that, a severe damage of the auditory nerve cannot be corrected or replaced.
7) Ways to look after the ears are: (a) prevent the ears from being exposed to
loud sound. (b) avoid digging the ears with sharp objects. (c) avoid from inflicting tight slaps onto the
ears. (d) clean up the ears with cotton buds
regularly so that the ear canal is not blocked.
LIMITATION OF SENSE OF HEARING1) The range of hearing frequency. (a) the human ear can only detect sound
between a frequency range of 20HZ to 20000HZ.
(b) the hearing range differs from one individual to another.
- it is harder for old people to hear because their eardrum are less elastic.
- for individuals who are exposed to continues sound pollution like loud sound of vehicles or machines, their ability to hear will decrease.
DEVICES OF HEARING1) STHETHOSCOPE= amplifies the sound of our heart beat so that it can be heard clearly.2) LOUDSPEAKER= makes sound louder so they can be heard from greater
distance.3) HEARING AID= makes sound louder so that people with hearing problems can hear clearly.
THAT’S ALL 4 THE SENSE OF HEARING
THE ENDTHANK YOU