# The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

By BYJU'S Exam Prep

Updated on: September 25th, 2023

The concave lens of power -1.25 D is required by the individual to correct his defect. A concave lens is required to remedy myopia the person has, which is a defect. An item at infinity should form its picture at the lens’s farthest point.

Now, the distance of the far point x = 80 cm

The focal length of the corrective lens must be long enough to see distant objects clearly.

f = -x = -80 cm

Power of the lens P (in meters) = (1/ 1/-80) = 1/-0.8 = 1.25

The lens is concave of power = -1.25D

The person must therefore use a concave lens with a power of -1.25 D to remedy his deficiency.

### Concave Lens

• A concave lens is one that bends a straight light beam away from the source and focuses it into a distorted, upright virtual image.
• Both actual and virtual images can be created using it.
• At least one internal surface of concave lenses is curved.
• Since it is rounded at the center and bulges outward at the borders, a concave lens is also known as a diverging lens because it causes the light to diverge.

Summary:

## The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

The far point of a myopic person is 80 cm in front of the eye. The concave lens of power -1.25 D is required by the individual to correct his defect. Concave Lenses make distant objects appear smaller than they actually are, they are used to cure myopia.

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