Geetha observes that a person needs a lens of power -4.5 D for correction of her vision. Few questions came to her mind. Give answers to the below questions:
1. What kind of defect in vision is she suffering from?
2. What is the focal length of the corrective lens?
(i) 0.9 m
(ii) 0.22 m
Q 3. What is the nature of the corrective lens?
(i) Convex lens
(ii) Concave lens
4. What is the formula for finding the focal length of the lens?
5. What is the unit for measuring the power of the lens?