Question

Doctor advised Ravi to use -2.5D lens to correct his eye defect. what is the eye defect of Ravi?​

Answer 1

power is negative which means focal length is negetive

only concave lens have focal length negative

we use concave lens to correct shortsightedness or myopia ( Ravi can't see far)

Answer 2

The eye defect of Ravi is myopia.

• The negative sign before the power of the lens indicates the lens is concave.
• A concave lens is used to diverge the rays of light before the retina. This results in the formation of the image on the retina thus correcting the defect.
• In the condition of myopia, the near objects are seen clearly but the objects at a farther distance do not appear clear.