A person can see objects clearly, when they are farther than 12.5 m away.
What type of lens and what type of power will allow the person to see distant objects clearly ?

Explanation

Distance of far point = x= 12.5 m
This defect can be corrected by using a concave lens of focal length f and
`f= -x = -12.5m`
Power of the corrective lens = P
`=(1)/(f("in m"))`
`P=(1)/(-12.5)= -0.08D`