Actually a good topic... I agree, putting rails in the shower or tub is pretty easy and basic.

A wheel'd office chair makes a decent wheelchair, assuming you don't run w/ 70's shag.

Glasses... well, they can be found cheap online, supposedly. Fortunately for me, when I deployed I recieved a second pair of glasses, 3 inserts for my ballistic eyewear, and bought 2 pair of wiley x glasses... so I think I'm set til I go blind.

Have a piece of plywood or two to help get up a few steps if you're in a wheelchair.

I think though, the most important thing would be furniture arrangement. You know, keep the bed by the restroom if you're bed confined. Near a power outlet, or with a lot of room around it, if you have durable medical equipment. Clear access to an outside door for EMS if you're invalid'd.