it doesn't really affect my friendships. i've grown into a very friendly and outgoing-too outgoing at times might I add- person.
I was recently talking about it with some of them recently and they all pretty much said that if it wasn't for the fact that i have to keep objects very close to my face when i'm reading, or that i need a little help for things that are afar, they really wouldnt know i was an albino. which i personally take as a major compliment.
Though to start with it's a bit hard, it's just little things they learn with time like if it's a really sunny day and i'll ask someone for their hand or elbow to walk, they won't mind, or they'll read out loud things that are far for me to read. it's nothing major and true friends won't mind doing these little things for you.
I used to feel very bad about it untill a while ago but then i learned it's not much i ask for and that "if they can't "deal" with being around me, then they re not worth my friendships".