The
Structure of the Eye
The eye is lodged in the bony
orbit. The 'White' of the eye is the Sclera. The dark part inside the eye is actually an opening
in the iris, called as the pupil. The central
transparent part is the cornea. The sclera is covered by the
membrane, conjunctiva. Inside the eye is fluid called aqueous.
Inner to the iris lies the lens. Behind the lens is the
jelly, called vitreous. The inner wall of eye is lined by
the retina. Between retina and sclera is the colored choroid.
The eye is connected to brain by
Optic nerve. The eye
muscles help in moving the eye.
The Eye
- How it works?
Simple! Yet so ingenious!
We have an outer transparent cornea, through which light
enters the pupil, the lens, the vitreous and is focused on the retina.
The
retina has the receptors called rods, which are sensitive to dim light and
cones, which are sensitive to bright light and to colours.
When the light
strikes these receptors, they get activated. That generates electro-chemical signals
.These are conducted via the optic nerve, to the brain .
The brain has a special
area called the visual cortex, which analyses these signals. It has connections
with other areas of the brain, thus we can interpret what we see!
What gives
colour to the eye?
The iris is the coloured part of the eye.
Depending on the amount of pigment it has, we get the colour
for the eye. Blue
colour ,when the pigment is least and
increasing amounts of pigments give
Grey, Green,
Brown and Black
colours. Albinos appear to have red eyes because they have very less pigment in
their iris. Thus the light is reflected from the Choroid, which looks red , due
to the blood vessels.
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