As a retiree I feel as if the OP's title and therefore his thread is a little condescending. It seems that older people or even those with eye problems who have trouble seeing should have to put up with smaller finer fonts in the name of design. At 72 years of age my eyes are not all that bad but I do appreciate when people take the time to ensure that I can read what they are writing. There are several magazines that I no longer purchase simply because they went to a smaller finer font in order to have less pages in their publication. Less pages means less paper and ink costs and therefore more profit, and to hades with the person who may have trouble reading it.
And speaking of hades, I hope there is a special place in the lower reaches of the infernals for those who put fine white text over light colors such as yellow or pale green, blue, orange, etc. Even using a magnifying glass you have trouble reading it. Some also like to go the other way as well and put black text over blue etc. At least the n you use an iPad or iPhone you have the ability to zoom in on areas when you may need to. But to have to constantly do it is a pain in the keister. Larger bolder text is the best solution.
Just remember a few years ago when Jony Ives went with the Helvetica Neue, and they had to go back to the straight Helvetica on the next go around because of the hullabaloo that the fine Neue text caused.