Question

The distance of the eye-lens from the retina is x. For a normal eye, the maximum focal length of the eye-lens

Options

•  = x

• < x

• > x

•  = 2 x

Answer 1

 = x

For a normal eye, we have:
Far point at which the object can be placed, u=∞

Distance between the eye lens and the retina, v=x

Thus, we have:

`1/f = 1/v-1/u`

`=> 1/f =1/x -1/∞`

⇒ f=x