Question

The entry of light in a photographic camera is controlled by the shutter and iris diaphragm, comparable structure in the human eye are
A. Cones and iris
B. Eyelids and iris
C. Ciliary muscles and pupil
D. Ciliary body and iris

Answer 1

Hint: Human eye is a very sensitive organ of the body that helps in the vision by entering the light into it.

Complete answer: Light is focused primarily by the cornea into the eye.
The cornea that is present on the front surface of the eye, is a clear part that acts like a camera lens.
The iris of the eye functions like the diaphragm of a camera that helps to control the amount of light reaching the back of the eye. It automatically adjusts the size of the pupil.
Eyelids act as shutters of our eye.

The two eyelids protect the eye and prevent the entry of excessive light by their closure.
The inner layer of the cornea is made up of transparent tissue that allows light to pass.

So, the correct answer is option B. Eyelids and iris.

Note: 1. Iris helps in dilating and constricting the pupil of the eye and help to allow more or less light into the eye. The iris has the ability to enlarge and shrink, which is dependent on how much light is entering the eye.
2. The pupil of the eye is the dark opening in the centre of the colored iris. It helps to control how much light enters the eye.
3. The ciliary body is a filamentous structure that is located behind the iris which produces aqueous fluid and fills the front part of the eye. It helps to maintain eye pressure. It also helps in the focusing of the lens.