The power of eye lens of normal eye where it is at its far point and near point respectively is ( assume the distance of the retina from the rye lens to be 2.5cm)

Asked by anshoomaurya04 | 20th Feb, 2020, 10:05: PM

Expert Answer:

Far point-
When object is at far point or infinity 
Eye lens is convex lens
f =2.5 cm = 0.025 m 
Thus,
P =1/f = 1/0.25 = +40 D
 
Near point or LDDV( 25 cm)
u =- 25 cm and v = 2.5 cm
Solving by using lens formula,
1/f = 1/v - 1/ u 
1/f = 1/ 2.5 - 1/(-25) 
f = 25/11 cm 
f = 25/ 1100 m 
P =1/ (1/ 25/1100) = 1100/ 25 =+ 44 D 
 

Answered by Shiwani Sawant | 23rd Feb, 2020, 08:52: PM