Question

Concave lens :: presbiopiya: …………​

Answer 1

Answer:

myopia

Explanation:

The lens capsule is attached to the ciliary body by a ligament and serves to refract and focus light rays on the retina. Loss of flexibility with age causes presbyopia, characterized by focusing on the image behind the retina. Likewise, too short eyeball causes hyperopia. In both cases, distant images are clear but the nearby images are blurry. Wearing of the convex lens is helpful in both presbyopia and hyperopia which bend the light rays and help focus the image on the retina.

On the other hand, myopia is caused by elongation of the eyeball which results in focusing of the image in front of the retina. Thus, the distant images are blurry but the nearby images are clear. Wearing of concave lens diverge the light rays to help the image to be focused on the retina; myopia is corrected using the concave lens.

Cataract is characterized by the presence of opaque lens, incapable of transmitting the light rays and is corrected by surgical replacement of lens with an artificial lens.

Answer 2

Explanation:

convex lens of focal length 10 cm is in contact with a concave lens. The focal length of the combination is numerically equal to that of the concave lens. The focal length of the concave lens is