Question

Mention the defects of human vision and describe the methods to remove them.

Hint:

Regular eye checkups help in early detection and correction of vision defects.

Answer 1

Step 1: To diagnose a vision defect, first identify the type based on where the image is formed relative to the retina:

In myopia (nearsightedness), the image is formed in front of the retina, causing distant objects to appear blurry.
In hypermetropia (farsightedness), the image is formed behind the retina, making nearby objects appear blurry.

Step 2: Correct the defect by using appropriate lenses that adjust the focal length so that the image forms precisely on the retina, ensuring clear vision:

For myopia, use concave lenses to diverge the incoming light rays, effectively moving the focal point backward onto the retina.
For hypermetropia, use convex lenses to converge the incoming light rays sooner, moving the focal point forward onto the retina.
This optical correction restores sharp vision by compensating for the eye’s improper focusing.