Question

What are the main parts of the eye? What are the eye's connections to the brain?

Answer 1

The structure of eye is very complex and unique.The eye focus on objects on the basis of distance and accomodate according to the light intensity entering into it.

The description of parts of eyes are as follows -

1) Orbit - It is the bony cavity in which the eyeball lies it contains nerves , blood vessels and duct( lacrimal) .

2) Sclera ( white of eye) - The outermost tough layer of eye which is white in colour.

3) Conjunctiva- The thin and transparent membrane which is of two types first bulbar conjunctiva which covers the eyeball and palpebral conjunctiva which is under the eyelids.

4) Cornea - Clear , curved and avascular layer which protects the eyes.It also helps in focusing light to retina on the back of eye.

5)Iris - Circular colored area of eyes which surrounds the pupil.

6)Pupil- Central hol in the iris through which light enters in the eyes.

7)Convex lens - Situated behind iris which focuses light on retina to form a sharp image.

8) Ciliary muscles - They helps to change the shape of lens by contacting and relaxing .

9)Retina - The back of eye on which the image is formed . It contains rods and cones.The most sensitive part of retina is called as macula .

The eye's connection to the brain -

Each photoreceptor is connected to optic nerve the nerve signal from each eye travels through corresponding optic nerve of the eye and meets at optic chiasma where the opposite signal travels to opposite part of brain left eye to right side of the brain. When the visual field of both these fields overlaps binocular vision is created.