Cat's vision

[janet]

Is it possible for a cat to develop night vision problems or (please don't laugh) become afraid of the dark? One of my guys is about 10 years old and his litter is downstairs. During the day he's fine, up and down as usual even sleeps on the couch there sometimes, but once it gets dark he sit's at the top of the stairs and meows until someone turns on the stair light. Even if his buddy goes down he won't follow.