Question

Explain all parts of human eye in detail.

Answer 1

Cornea The cornea is the outermost layer of the eye and is primarily responsible for focusing the light that comes into our eyes. There are 5 layers to the cornea. The outer layer acts as a kind of shield to the elements and can usually repair itself within a few days of suffering a minor injury. The deeper layers exist mainly to strengthen the eye.

Pupil The pupil is the black circle in the center of the eye, and its primary function is to monitor the amount of light that comes into the eye. When there is a lot of light, the pupil contracts to keep the light from overwhelming the eye. When there is very little light, the pupil expands so it can soak up as much as possible.

Iris The iris is the colored part of the eye. Although it might seem purely cosmetic, the iris actually functions to adjust the size of the pupil. It has muscles that contract or expand depending on the amount of light the pupil needs to process images.

Lens The lens exists behind the pupil and is responsible for allowing your eyes to focus on small details like words in a book. The lens is in a constant state of adjustment as it becomes thinner or thicker to accommodate the detailed input it receives. With age, the lens loses a lot of its elasticity which often results in cataracts and presbyopia because the lens cannot adjust as well to its surroundings as it used to.
Retina The retina is the area at the back of the eye that receives the refined, visual message from the front of the eye, and it transmits that visual message to the brain using electrical signals.

Answer 2

The sclera, or white part of the eye, protects the eyeball. The pupil, or black dot at the centre of the eye, is a hole through which light can enter the eye. The iris, or coloured part of the eye, surrounds the pupil. The cornea, a clear window at the front of the eye, covers the iris and the pupil.