Some of my guys will just sleep on top of an unwanted friend in their bed If that is where they want to sleep, then it doesn't matter if there is another one in the same bed.

I don't let any of my guys outside (because all my neighbors have BIG dogs), but they do like hanging out by the windows.

I have had blind cats for about 6 years and we have always been in the same house, and every once in a while they still have trouble. But I have never had to take them into the vet for that reason, so all is well.