A bifocal lens is used to correct which of the following defects of vision?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Presbyopia
In presbyopia, which comes with age, the ciliary muscles weaken and the eye lens loses its flexibility, so near objects cannot be seen clearly; many such people cannot see distant objects clearly either. A bifocal lens corrects both: its upper part is a concave lens for distant vision and its lower part a convex lens for reading.