Question

The entry of light in a photographic camera is controlled by the shutter and iris diaphragm, comparable structure in human eye are

• A. Cornea and iris
• B. Eyelids and iris
• C. Ciliary muscles and pupil
• D. Ciliary body and iris

Answer 1

The correct option is B Eyelids and iris

Iris is the part of the eye, which acts like the diaphragm of a camera, dilating and constricting the pupil to allow more or less light into the eye. The iris works like a shutter in a camera. It has the ability to enlarge and shrink, depending on how much light is entering the eye.
The two eyelids act to protect the front of the eye and excessive light by their closure. The inner layer of the cornea is made up of transparent tissue, which allows light to pass. The pupil is the dark opening in the centre of the coloured iris, that controls how much light enters the eye. The ciliary body is a structure located behind the iris which produces aqueous fluid that fills the front part of the eye and thus maintains the eye pressure. It also allows focusing of the lens.

Thus, the correct answer is the option (B).