Possible eye problem

Hopefully I'm worrying about nothing, but here goes anyway. I came in from work & noticed a very slight swelling on Max's right eyelid. It actually looks as if there is a bald patch there, although this may be the swelling. He's been rubbing it a bit, so it may just be a case of him having a bit of an itch, which could have caused it to swell. Anyway, I've posted a picture, so if anyone can put my mind at ease I'd be grateful!
Thanks.

I used to notice something very similar with my black kitty (also was named Max!). Maybe it's just more noticible because he's dark? I would just keep an eye on it (sorry for the pun ) and if it gets worse I would take him in to the vet.

Karen