Question

a person needs a lens of power + 2.5 D for correcting his vision name the defect of vision he is suffering from which type of lens will he be using for collecting the defect also find the focal length of the lens

Answer 1

He is suffering from hypermetropia and the length of focal length is 2.5+2.5=5cm

Answer 2

The defect is hypermetropia. He is using covex lens for correcting the defect.

Power= +2.5 D

P=1/f
f=1/P
f=1/2.5
f=2/5
f=0.4m

the focal length is 0.4m