@Jax If she's wearing them all the time, it's because she's farsighted and her lenses are convex. If they could find reading glasses, those would work.
*edit: she's nearsighted, needs concave glasses to see far. Farsighted people need convex reading glasses.
@Esper that's very neat. I have to say, lenses are one of the subject I did the worst on in physics so that goes beyond my head. But I'll take your words for it