Question

The lens used in spectacles for the correction of short-sightedness is a

• A. Concave lens
• B. Convex lens
• C. Plano-convex lens
• D. None of these

Answer 1

The correct option is A Concave lens

The medical name for short-sightedness is myopia.

Myopia occurs when light is focused in front of the retina. It occurs because either the eyeball is too long, or because the cornea is too curved.

The safest way to correct short-sightedness is with glasses. Concave prescription lenses (called minus lenses) are used to bend light rays slightly outwards. The light rays then have a greater angle to bend back to focus when travelling through the cornea and lens.

As a result, the light rays focus further back - on the retina. thus concave lens are used to correct short-sightedness, Hence Option A is correct.