Question

3. A person can see clearly objects between 15 and 100 cm from his eye. Therange of his vision if he wears close fitting spectacles having a power of0.8 diopter is1) 5 to 500 cm 2) 12 to 250 cm 3) 17 to 500 cm 4) 17 to 250 cm​

Answer 1

Answer:

3.    17 to 500 cm

Explanation:

If he wears glass with power of-0.8 , then he would have residual -0.20D of myopia for distance and for near he would be able to see with the equivalent of -5.87D of myopia. This translates to range of clear vision with those glasses from 1/0.2=5 meters to 1/5.87=0.17 meters i.e. 17cm to 500cm.