Question

a student is unable to see clearly the words written on the black board placed at a distance of approximately 3m from him . name the defect of vision the boy is suffering from . state the possible causes of the defect and explain the method of correcting it .

Answer 1

The defect is myopia
Causes- excessive curvature of the eye lens;elongation of the eyeball
X=3m
Focal length = -x
So f =-3
Power =1/f =1/-3 = -0.333D
Hence a concave lens of power -0.333D is required to correct the defect

Hope it helped ta

Answer 2

not having of vitamin a