Question

A doctor has prescribed a corrective lens of power 20 diopter to a person suffering from some defects of vision question mark first identify the defect from which he is suffering second find focal length of lens third is prescribed lens diverging or converging fourth state some causes of the defect

Answer 1

Answer:

ask the doctor.........

Answer 2

Answer:

firstly since the power is positive it's focal length is also positive which means it is a convex lens now convex lens is used in case of myopia means the patient is suffering from myopia

now the focal length::

P=1/f

20D=1/f

f=1/20

f=0.05m

f=5cm

it is a converging lens

now there are 2 causes for this disease

1. firstly It may be hereditary
2. secondly it may be for the abnormal eyeball from birth