Question

A 52 year old nearsighted person wears a glass with the power of minus 5.5 diopters for his distance viewing his doctors prescribe a correction of + 1.5 diopters in the near vision for his bifocals . this is measured relative to the main part of the lens .
what is the focal length of his distance viewing part of the lens ?
what is the focal lens office near vision section of the lens ?

Answer 1

Distance viewing:-

P = 1/f

Therefore, f = 1/P

So, f = 1/-5.5 = -0.45m

Near vision:-

P = 1/f

Therefore, f= 1/P

So, f = 1/1.5 = 0.67m

HOPE THIS HELPS!

Answer 2

answer is 0.67 I hope help u