For a normal eye, the cornea of eye provides a converging power of `40 D` and the least converging power of the eye lens behind the cornea is `20 D`. Using this information, the distance between the retina and the cornea eye lens can be estimated to be

Options

A. 1.5 cm
B. 5 cm
C. 2.5 cm
D. 1.67 cm

Answer

D

Explanation

P = 40 + 20 = 60 D
The distance between the retina and the cornea eye to lens must be equal to f
`therefore " " f = (1)/(P) = (1)/(60) m ` = 1.67 cm.