Pug bite or sting next to eye

Hi, Yesterday evening, when I took my pug for a walk something must have stung or bit him right underneath his eye. He wanted to be held more than usual that night and that's when I saw he couldn't open his eye all the way because it was swollen. I gave him some benedryl and tried to put a compress on it.  He kept waking me up all night just for comfort.  Right now a day later it seems to be a little better but he has a lot of tears drying up inside his eye and it is still swollen (not nearly as bad). The benedryl had seemed to cause urine retention and he couldn't go to the void at all day.  Finally he just went about ten minutes ago. As a caregiver I want to know if there is anything further I can do for him? The benedryl seems to help the reaction but I don't want him to have anymore issues voiding.  Are there any human eye drops that I can use? Are there any other recommendations?
Thank you for help whoever is out there!

[Ghilly]

You can try taking some buffered saline solution (for humans, available at any grocery store), soaking a cotton ball with it, and holding it over the eye for a while.  This will help keep the area clean without being irritating to the eye itself.  You can also try making a solution by brewing a cup of chamomile tea, allowing it to cool, and using that as a wash for the area.  Otherwise, as long as the swelling is going down and the area is looking better, it sounds like you are on the right track.  

Ghilly