Question

Which of the following lenses of appropriate focal length is used to correct shortsightedness ?

• A. Concave
• B. Convex
• C. Both A & B
• D. None of the above

Answer 1

The correct option is A Concave

A convex lens of appropriate focal length is used to correct farsightedness.
Farsightedness is the inability to see nearby objects clearly due to the formation of image by convergence of rays at a point behind the retina. A convex or converging lens with the correct focal length allows the rays to converge at a point on the retina. The convex lens first converge the rays before it reaches the eye and thus, reducing the image distance. The eye-lens will now be able to converge the refracted rays ton the retina.