Nooper needs a lens of power `- 4.5 D` 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 corrective lens ?
( c) Draw ray diagrams showing the defected eye and correction for the defect.
(d) What are the causes of this defect ?

Explanation

(a) As power of lens is negative, she must be suffering from myopia.
(b) As `f = (100)/(P) :. F = (100)/(-4.5) = (-100 xx 2)/(9) = -22.2 cm`.
( c) The corrective lens must be concave.