The accomodation power of the eye lens of a young man whose far point is infinity can vary from 40D to 44D. Answer the following
- What does the statement means?
- What is the distance of retina of the eye from the eye lens?
- What is the position of near point of eye for the young man?
- When the eye is focused at a near point, the eye lens has a power of 44 D
- When the eye is fully relaxed (i.e focused at infinity), the power of the eye lens is 40 D
When the eye is fully relaxed, object distance is infinity, and image distance is equal to the focal length of the eye lens.
Therefore, the distance of the retina of the eye from the eye lens is equal to the focal length of eye lens when the eye is fully relaxed.
f = 1/P
f = 1/40
f = 2.5 cm
The distance of the retina from the eye lens is 2.5 cm.