Question

How does the eye adjust to take account of an increase in brightness?

Answer 1

Hint:Light ray enters through the cornea of the eye, which passes through the pupil of the eye and falls on the eye lens. As we know that the eye lens is a converging lens, so it converges all the light at one point and produces a real and inverted image of the object. Also, If brightness is more then the pupil of the eye shrinks.

Complete answer:
The human eye works on the refraction of light through a natural convex lens which is made up of transparent material which enables us to see things that are around us. Human eye contains- Cornea, Iris, Pupil, Ciliary muscles, eye lens, optic nerves and retina.

As we all know that the pupil of the eye is a hole located in the centre of the iris of the eye that part allows light to strike on the retina. It appears black in colour because light rays entering the pupil are either absorbed by the tissues inside the eye directly or absorbed after the diffuse reflections inside the eye. When there is an increase in brightness then the pupil of the eye shrinks and less light will pass into the eye.

Note: The image formed on the retina is conveyed to the brain through optic nerves and gives a sense of vision. When the image falls on the retina then these light sensitive cells get activated and they generate electric signals. The image formed on the retina is inverted.