Swollen eye on Syrian :(

[bertieboo101]

Hi guys,
My 2.5 year old Syrian Bertie is still a happy chappy, walking around, eating, up for cuddles and seems ok. I noticed today his right eye was quite dry, and seemed raised/swollen. He is loosing his hair and obviously getting old bless him.. I’ve been dreading these days! I just don’t know if he is in any pain. I want to avoid the vets if he is ok and no reason to worry just yet, as i know considering his age what they will suggest Has anyone experienced this before or does anyone have advice? I’m not massively worried yet, but again I have no idea if he is in pain.. Any help would be appreciated