Question

Write a detailed note on structure and function of eye?

Answer 1

Shape: -

Eye is small organ. It is spherical in shape.

Size: -

The eye is 2.4cm in diameter.

Location: -

Each eye is present in bony socket called orbit. Socket also contains muscle that

move eye ball.

Eye Lids: -

Eyelids are present upper and lower of each eye.

Parts of Eye: -

i) The outer most layer of eyeball is whitish in colour and form cornea.

ii) The second layer of eyeball is called choroids.

iii) Behind cornea choroids bends inwards to form Iris having circular

opening called pupil.

iv) Behind pupil a biconvex lens is present.

v) The innermost layer of eye is called retina.

Sensory Cells: -

The sensory cells of eye have two types: -

a) Rods b) Cones.

These cells help in the formation of image on retina above the point of entry of optic

nerve called blind spot.

Tear Glands: -

Tear glands are also present in the socket. The secretion of these glands washes the

eyes.

Image Formation on retina: -

i) The light rays coming from object focuses from retina.

ii) They rays are focused in a special spot called fovea centralis.

iii) This spot produce sharp image.

iv) Lens plays important role by changing its convexity to produce enough

refraction.

v) Al last it bring the image into focus and form a clear image on retina