A short sighted person is wearing specs of power `-3.5 D`. His doctor prescribes a
Channel: Doubtnut
Date: 2020-08-02

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 ?