They have nerves and tissues that send signals to the brain to create a visual image. One of these critical tissues is the retina, which is at the back of the eye.
The retina plays a crucial role in sending visual signals to the brain, and it contains small and large arteries and veins that move blood to and from the heart.
This blood is essential to vision, and a blockage in the retina's blood vessels can permanently affect vision and lead to blindness.
**Eye is a crucial and essential part of the body,it is held by series of lateral muscles.Blinking of eye is an involuntary reaction because it is inevitable to open an eye without blinking it.An eye is a specialized sense organ for detecting light.It has three layer namely sclera,choroid and the retina.
##Parts of an eye and their function#
conjunctiva-protect cornea
cornea-It is responsible for protection of part of eyeball.
suspensory ligament-It holds lens in position and attach it to ciliary body
lens-for correction of sharp rays of light on the retina.
Aqueous humour-watery liquid that fills the space in front of lens also supplies oxygen and nutrient for eye
Iris-It controls amount of light entering eye.
pupil-light enters the eye through pupil
Vitreous humour-helps to maintain the shapeof an eye.
Optic nerve-It transmits sensory impulses from retina to brain
Blind spot-Light insensitive spot where optic nerve leaves eye.
Yellow spot(fovea centralis)-Most sensitive part of retina where light are usually focused.
##Defects of mammalian eye##
All these are treatable by a medical professional
short sightedness- This condition is also known as near sightedness or myopia.people who are short sighted can See nearby object clearly but distant ones appear blurred.
long sightedness hypermetropia -people who are long or far sighted can see distant objects clearly but nearby ones appear blurred.
Astigmatism -in certain cases of astigmatism, vertical figures can be seen clearly but horizontal figures appear blurred.
Retinoblastoma-is a rare cancer that develop from immature cells of retina which leads to inflammation of the retina.
**Cataract-is a clouding of the eye's natural lens,which leads to decrease in vision.
Night-blindness -people with night blindness cannot see clearly in dim light.
Xerophthalmia- This is an eye disease caused by vitamin A deficiency. It can lead to blindness.
conjunctivitis-This is an inflammation of the conjunctiva. It is a very contagious infection caused by bacteria.
Strabismus- is a condition in which the eyes do not properly align with each other when looking at an object
##Causes of eye defect##
old age
Malnutrition or lack of vitamin such as vitamin A(retinol)
poor hygiene habits
**irritants such as wind and glare, germs in the air(bacteria)
Having sleepless nights
##Care of the mammalian eye##
We should care for our eyes by
use of clean handkerchief to clean the
eye while itching
Do not rub the eye with dirty fingers
Reading books with fairly large prints and under correct lighting conditions
By seeing doctor in case of eye infections so that he can prescribe proper spectacles to use.
By getting enough sleep
Eating more fruits and vegetables
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Three photos added from google
My advice for everyone is that protect your eyes care for your eye and allow it to rest at appropriate time.Thanks
Cool!
Thanks