Question

Name two defects of vision, mention their case and the type of lenses to correct them.

Answer 1

Hint
The ability to see something is known as the vision. Some of the time the eye of a person cannot focus on the image of an object on the retina properly, this results in the defects of vision.

Complete step by step answer
Some of the defects of the eye are as follows-
Myopia (near-sightedness):
myopia is a defect of the vision in which the far away objects appear to be unfocused but the nearer objects can be viewed clearly. The image of the object is focused in front of the retina comparatively than on the retina usually, this is due to the reason the eyeball is too long or the refractive power of the eye’s lens too strong. Myopia can be corrected by wearing glasses with concave lenses of appropriate power to help to focus the image of the object on the retina.
Hyperopia (far-sightedness):
hyperopia is a defect of vision in which the image of the object is difficult to focus with near vision but far away objects can be focused easily. The image of the object is focused behind the retina comparatively than on the retina. This happens when the eyeball is too short or the refractive power of the lens is too weak. Hyperopia can be corrected by wearing glasses that contain convex lenses of appropriate power to help to focus the image of the object on the retina.

Note
The leading causes of blindness and defects in vision around the world are mostly due to the age-related eye diseases such as age-related macular degeneration, cataract, diabetic retinopathy, and glaucoma.