Human Eye and the Colourful World

What is Cornea?

Cornea is the thin transparent membrane which forms a bulge on the outer surface of the eyeball.

The eyeball is approximately spherical in shape and has a diameter of about 2.3 cm.

Light enters the eyes from this membrane.

Most of the refraction of light rays entering the eye occurs at the outer membrane of the cornea.

What is Retina?

Retina is a screen at the back part of the eye on which images are formed.

It is a delicate membrane having an enormous amount of light sensitive cells.

These cells get activated on illumination and generate electrical signals that are sent to the brain via the optic nerve.

The brain interprets these signals and enables us to percieve objects as they are.

What is eye lens?

The eye lens is a crystalline lens that is made up of transparent and flexible tissues.

It helps the eye to focus light rays on the retina by changing its focal length.

What are the Ciliary Muscles?

Ciliary muscles are present as a ring of muscles that can relax and contract and help the eye lens to change its focal length.

What is the iris?

The iris is a dark muscular diaphragm that lies behind the cornea and controls the shape of the pupil