question_answer

Myopia is a defect of vision caused by

A)  a decrease in the retinal distance from the lens

B)  a decrease in the diameter of the eyeball

C)  an increase in the thickness of the lens

D)  an increase in the curvature of the lens

Correct Answer: D

Solution :

  In a myopic eye, the image of distant objects is formed in front of the retina and not on the retina, as shown in the given figure. Since eye lens is convex, all parallel rays converge at its focus. This is a clear indication of the shortening of the focal length of a myopic eye lens. As a result, the curvature of the lens gets increased. Hence, myopia is caused by an increase in the curvature of the eye lens. The correct answer is D.