The near point of a defective eye is `25 cm` from the eye. Calculate focal length of the lens required by her to read a book placed at `20 cm`.

Focal length of eye lens is changed by

The near point of a hypermetropic person is 50 cm from the eye. What is the power of the lens required to enable him to read clearly a book held at 25 cm from the eye ?

The near point of a hypermetropic person is 50 cm from the eye. What is the power of the lens required to enable him to read clearly a book held at 25 cm from the eye ?

The far point of a myopic eye is 10 cm from the eye. The focal length of a lens for reading at normal distance ( 25cm) is

The far point of a myopic person is 150 cm in front of the eye. Calculate the focal length and power of a lens required to enable him to see distant objects clearly.

The far point of a myopic person is 150 cm in front of the eye. Calculate the focal length and power of a lens required to enable him to see distant objects clearly.