Question

what is myopia and hyperopia? How can we correct these?

Answer 1

Myopia:

In Myopia or near-sightedness, the distance between the distance between the cornea and the retina is too long so that the light ray is focused in front of the retina instead of on it . Also, close objects in myopia will look clear but distant objects will appear blurred .

Correction:

To correct the problem the lens must be weakened. In order to do so, a diverging or negative artificial lens is used., that is commonly called Concave lens.

A diverging lens (concave lens) tends to be wider at the edges than at the middle. Because of that, lights spreads out even more after the light has passed through the lens than before.

Hyperopia:

Hyperopia is a common form of mild visual impairment. It is often called farsightedness because faraway objects are clearer than nearby objects to see. In this case, the eye tends to be too short for the lens. The process of accommodation does not make the lens thick enough to focus on the light from more close objects onto the retina. Because these close objects are being focused behind of the retina instead of on it, the objects will appear blurry.

Correction:

A converging or positive artificial lens is used to strengthen the lens which is also called convex lens. This type of lens is wider in the middle that the edge like the lens of our eye which adds more focusing power to the lens.