Question

The picture given here shows a person wearing ‘half-moon’ spectacles. What sort of eye-defect do you think he has? Why are these particular spectacles useful to him?

Answer 1

As the person is wearing half-moon spectacles, he should be suffering from the eye defect called long-sightedness, or hypermetropia, because his spectacles are fitted with a convex lens. The convex lenses form the images of nearby objects at the near point of his eye, and he can, therefore, see these objects clearly.