A doctor has prescribed a corrective lens of power + 1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?

Question

Philoid · Accepted Answer

The power of this lens is positive (with a plus sign), therefore, this is a convex lens or converging lens. Now,

Power, P =

So, +1.5 =

Or m

cm

So, Focal length of lens, f = +66.7 cm.