Question

Consider the following statements in the context of human eye:
(a) The diameter of the eye ball is about 2.3 cm.
(b) Iris is a dark muscular diaphragm that controls the size of the pupil.
(c) Most of the refraction for the light rays entering the eye occurs at the crystalline lens.
(d) While focusing on the objects at different distances the distance between the crystalline lens and the retina is adjusted by ciliary muscles.
The correct statements are –

• A. (a) and (b)
• B. (a), (b) and (c)
• C. (b), (c) and (d)
• D. (a), (c) and (d)

Answer 1

Answer: (A)

(a) and (b)

Answer 2

• (a) The diameter of the eyeball is approximately 2.3 cm. (Correct)
• (b) The iris controls the size of the pupil. (Correct)
• (c) Most refraction occurs at the cornea, not the crystalline lens. (Incorrect)
• (d) The distance between the crystalline lens and the retina is fixed; ciliary muscles adjust the focal length of the lens. (Incorrect)