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 -

Question

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 - (A) 1.5 cm (B) 5 cm (C) 2.5 cm (D) 1.67 cm

Tardigrade Admin · Accepted Answer

For a normal eye, rays coming from infinity should go the retina without effort when we look at infinity, lens offers minimum power and hence combination gives 40D + 20D = 60D.
Distance between the retina and the cornea eye has must be equal to focal length.

f = \frac{1}{60} m = 1.67 c m

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

1.5 cm

5 cm

2.5 cm

1.67 cm

For a normal eye, rays coming from infinity should go the retina without effort when we look at infinity, lens offers minimum power and hence combination gives 40D + 20D = 60D. Distance between the retina and the cornea eye has must be equal to focal length. f=601​m=1.67cm

Q. 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 -

For a normal eye, rays coming from infinity should go the retina without effort when we look at infinity, lens offers minimum power and hence combination gives 40D + 20D = 60D.
Distance between the retina and the cornea eye has must be equal to focal length.
$f = \frac{1}{60} m = 1.67 c m$