Saved Bookmarks
| 1. |
Sha went to a doctor and said that he could not see distant objects clearly. Doctor tested and prescribed a lens of power - 0.75 D. a. what is the eye defect of sha ? b.Why did the doctor prescribe a lens - 0.75 D ? c. What type of lens is this ? |
|
Answer» <P> Solution :a. Short sightB. Power of lens = - 0.75 d `therefore` FOCAL length , F = `(-1)/(P) = (-1)/(0.75) = (-100)/(75) = (-4)/(3) ` m A short sighted person can see only nearby OBJECT clearly. By using a concave lens of power - 0.75 D, the image is made to fall on the retina. c. the concave lens |
|