Eye Lens Refractive Power?

A student is reading a lecture written on a blackboard. The lenses in her eyes have a refractive power of 68.80 diopters, and the lens-to-retina distance is 1.461 cm.

(a) How far (in meters) is the blackboard from her eyes?

(b) If the writing on the blackboard is 5.70 cm high, what is the size of the image on her retina (including the proper algebraic sign)?

This is an interesting question that many people are asking. And why? Because people want to know the answer to this question. That is why!