For which condition would a diverging lens be used for correction?

• A. Myopia
• B. Hyperopia
• C. Presbyopia
• D. Astigmatism

Answer: (A)

A diverging lens is used to correct myopia, or nearsightedness, because it helps to expand the diverging rays of light that come from distant objects so that they can focus correctly on the retina. In individuals with myopia, the eye is typically too long, causing light rays to converge before they reach the retina, resulting in distant objects appearing blurry. The diverging lens counteracts this by spreading the light rays apart, allowing them to extend the focal point back onto the retina, thus leading to clearer vision at distance.

In contrast, conditions like hyperopia (farsightedness) require converging lenses to bring the focus closer to the retina for near objects. Presbyopia, which is an age-related condition characterized by difficulty in focusing on near objects due to loss of lens elasticity, also typically requires converging lenses for correction. Astigmatism results from an irregularly shaped cornea or lens, causing distorted images, which can be corrected with cylindrical lenses that neutralize this irregularity. Thus, myopia is the only condition listed that is effectively corrected with a diverging lens.