Question

List two causes of this defect.

Hint:

For correcting hypermetropia, convex lenses are used, and their power is calculated as \( P = \frac{1}{f} \). A positive power indicates the use of convex lenses.

Answer 1

The primary causes of hypermetropia are:
1. Shortened eyeball: If the eyeball is too short, the image will focus behind the retina.
2. Weak curvature of the cornea or lens: Insufficient bending of light rays by the cornea or lens prevents proper focus on the retina.