Question

a person needs a lens of power -5.5 diopters for correcting his distant vision. for correcting his near vision he needs a lens of power 1.5 diopter. what is the focal lenght of the lens required for correcting 1} distant vision 2} near vision

Answer 1

for distant vision the focal length = 1/-5.5= -0.18cm and for near 1/1.5= 0.667cm