Question

After testing the eyes of a child, the optician has prescribed the following lenses for his spectacles: Left eye: = +2.00 D and Right eye = +2.25 D. The child is suffering from the defect of vision called:

• A. Myopia
• B. Hypermetropia
• C. Presbyopia
• D. Astigmatism

Answer 1

The correct option is B

Hypermetropia

Power of a lens is inversely proportional to focal length.

$\Rightarrow$ $P=\frac{1}{f}$

If the focal length is positive, the power of the lens will be positive. Therefore focal length will be positive for a convex lens.

Here, the power of the rectified lens prescribed by the optician is positive, hence it is a convex lens.

The convex lens of appropriate power is used for rectification of hypermetropia. So, the child is suffering from hypermetropia.