What is human eye || Structure of human eye || functions of human eye ||Short note on human eye||pointwise structure of eye.

 The human eye: Structure and Function

Structure of eye

∆Cornea

∆lens

 ∆ciliary muscles

 ∆Iris and pupil

 ∆retina

∆ optic Nerve

1. Cornea - 

• work as protective layer

 •most reflection done by it 

•outer part of eye which transparent and bulked out.

Lens

 •bi convex lens of very short focal length

 •placed by ciliary muscles 

ciliary muscles

 •adjust focal length 

•control lens keep lens at proper position Iris 

•present between cornea and lens 

•it is dark muscular diaphragm 

pupil

• it is aperture which regulates amount of light enter 

retina

 •image made on it it is light sensitive layer optic nerve 

•send signal to brain

•also called sensory nerve

Function of human eye:

(i) When light strikes the eye ball, it is refracted first by the cornea.

(ii) It then enters the eye ball through pupil.

(iii) The iris muscles guard the size of the pupil and regulate the amount of light that enters the eye.

(iv) The entering light now passes through the eye-lens. The eye-lens focuses the light rays on the retina.

(v) The eye-lens is a biconvex lens and forms a real and inverted image on the retina (as shown in following Fig. 10.6).

(vi) When light rays fall on retina, the light-sensitive cells (rods and cones) get activated and generate electrical impulses (signals).

(vii) These signals are sent to the brain via the optic nerves. The brain interprets these signals (make the image erect) and finally processes the information.