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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 eye lens of the eye can be estimated to be
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- 2.5 cm
- 1.67 cm
- 1.5 cm
- 5 cm
Correct Option: B
Pcornea = + 40 D
Pe = + 20 D
Total power of combination = 40 + 20 = 60 D
Focal length of combination = | × 100 = | cm | ||
60 | 3 |
For minimum converging state of eye lens,
u = -∞ V = ? f = | ||
3 |
From lens formula, = | = | - | ⇒ v = | cm | ||||
f | v | u | 3 |
Distance between retina and cornea-eye lens
= | = 1.67 m | |
3 |