A person wears eye glasses with a power of `-5.5 D` for distance viewing. His doctor prescribes a correction of `+ 1.5 D` for his near vision. What is the focal length of his distance viewing part of the lens and also for near vision section of the lens ?

A short sighted person is wearing specs of power -3.5 D . His doctor prescribes a correction of + 2.5 D for his near vision. What is focal length of his distance viewing part and near vision. What is focal length of his distance viewing part and near vision part ?

A doctor prescribes a person (i) power of -5 D for distant vision correction (ii) power of +2 D for near vision. Determine the focal length of both the parts of corrective lens.

The power of lens is 2.5 D . What is its focal length ?

Noopur needs a lens of power-4.5 D for correction of her vision. What are the causes of this defect?

Doctor has presecribed a lens having power + 1.5D. What will be the focal length of the lens ? What is the type of the lens and what must be the defect of vision ?