Question

Noopur needs a lens of power -4.5D for correction of her vision.
a)what kind of defect in vision is she suffering from ?
b)what is the focal length and nature of the corrective lens?
c)draw a ray diagram i)defected eye and ii)correction for ths defect
d)what are the causes of this defect?

Answer 1

a) she is suffering from Myopia
b) The correction lens is diverging lens
focal length is 1/4.5 = 10/45= 2/9 cm
c) ray diagram in ncert book
d) causes.
1. decrease in focal length
2. elongation of eye ball