The function of the convex lens in the correction of eye defects is to

Analyzing the question: It asks what a convex lens does when used to correct an eye defect.

Concept:

• A convex (converging) lens is thicker in the middle and bends light rays inward so they meet at a point.
• The eye defect it corrects is long-sightedness (hypermetropia). In this condition, the eyeball is too short or the lens is too weak. Light from near objects would focus behind the retina, so the person sees near objects blurred.
• The convex lens adds extra converging power, so the rays are bent inward enough to focus exactly on the retina.
• A concave (diverging) lens does the opposite. It corrects short-sightedness (myopia), where the image forms in front of the retina.

Checking the options:

• A. Wrong. "Diverge" describes a concave lens.
• B. Wrong. Focusing behind the retina is the defect itself, not the correction.
• C. Wrong. Focusing before the retina is the myopia problem, and the option also contains a typo ("time image").
• D. Converging light rays so the image falls on the retina is exactly the job of a convex lens.

Note on the wording: Option D says "from far objects". Strictly, a convex lens corrects long-sightedness, which concerns near objects. Still, D is the only option that correctly says the lens converges light to focus the image on the retina.

Answer: D

Exam tip: Remember "Convex = Converge = Corrects long-sight (far-sighted)". Concave lenses diverge and correct short-sightedness. In any option set, eliminate anything that says the image is focused before or behind the retina, because that describes the defect and not the cure.