Worried about my dad

I have recently noticed that my dad seems to be having more trouble with his eyes lately, and I am worried he might be beginning to suffer from macular degeneration. Can anyone tell me where I can find out more about macular degeneration symptoms? He says his vision is a little blurry, and he seems to be needing more light to read. He thinks it is just that he is getting old, but I want to convince him to get checked out to make sure it isn’t something that could be helped. I really don’t want him to lose his vision if he doesn’t have to.