Question

Consider the following statements:

1. Ciliary muscles adjust for changing the intensity of light entering the eye.
2. Myopic eye can be corrected by converging lenses of suitable power.
3. The function of the pupil is to regulate the quantity of light entering the eye.
4. When ciliary muscles are completely relaxed, the focal length of the eye lens is maximum.

The correct statements are:

• A. i, ii and iv
• B. i, ii and iii
• C. iii and iv
• D. ii and iv

Answer 1

The Correct Option is C

Let’s analyze each statement:

i. False. Ciliary muscles control the shape of the lens (accommodation), affecting the eye’s focusing ability, not the intensity of light. The intensity is controlled by the iris and pupil.

ii. False. Myopia (nearsightedness) is corrected using diverging lenses, not converging lenses. Converging lenses are used to correct hyperopia (farsightedness).

iii. True. The pupil, the opening in the iris, regulates the amount of light entering the eye by constricting (reducing size) in bright light and dilating (increasing size) in dim light.

iv. True. When the ciliary muscles are relaxed, the lens is at its least curved state, resulting in the maximum focal length. This allows for focusing on distant objects.

Therefore, only statements iii and iv are correct.