Maybe his eyesight is begining to fail a la Freedom lost ?

He may now be suffering from hypermetropia (long sightedness), hence he can see clearly at long distances but poorly at short ? His glasses may be such that they only help when doing extreme close up work ?

That is if they are taking continuity into account here -which I doubt ?

Yes he is injury prone, but Ryan would never leave his oldest and truest friend.  Not only that Midlred would have to be knocked off or she would just lose it without the companionship (like an old married couple), it is the only thing she lives for in a world that is not her own.