The far point of a myopic person is 80 cm in front of the eyes. What is the nature and power of the lens required to enable him to see very distant objects distinctly ?
For a myopic eye, the correcting lens is concave. Distance of far point, x = 80 cm, P = ?
For viewing distant objects, focal length of corrective lens,
f = -x = -80cm
Using the relation
P= 1/f = 100/-80 = -1.25D