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.

Answer

`-1.5 m, -0.67 D`

Explanation

Here, `v = x = - 150 cm, u = oo, f = ?`
From `(1)/(f) = (1)/(v) - (1)/(u) = (1)/(-150) - (1)/(oo)`
`f = - 150 cm = - 1.5 m`
`P = (1)/(f) = (1)/(-1.5) = -0.67 D`