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`.

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.

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.

(a) The near point of a hypermetropic person is at 75 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 ? (b) In what way does the corrective lens help the person above ? Does the lens magnify objects held near the eye ? ( c) The person above prefers to remove his spectacles while looking at the sky. Explain why ?

The near point of a hypermetropic eye is 50 cm . Calculate the power of the lens to enable him to read a book at 40 cm ?