How does a diverging lens correct myopia?

A diverging lens corrects myopia by diverging the incoming light rays before they reach the eye.

Myopia, also known as nearsightedness, is a condition where the eye is unable to focus on distant objects. This is because the eyeball is too long or the cornea is too curved, causing light rays to converge in front of the retina instead of on it. As a result, distant objects appear blurry.

A diverging lens is a concave lens that causes light rays to spread out or diverge. When placed in front of a myopic eye, the diverging lens diverges the incoming light rays even further before they reach the eye. This reduces the overall convergence of the light rays and moves the focal point back to the retina, allowing the eye to focus on distant objects.

The amount of divergence required depends on the severity of the myopia. A stronger diverging lens is needed for a more myopic eye, while a weaker lens is sufficient for a less myopic eye. The power of the lens is measured in dioptres, with a higher negative value indicating a stronger lens.

In summary, a diverging lens corrects myopia by diverging the incoming light rays before they reach the eye, reducing the overall convergence of the light rays and moving the focal point back to the retina.