Thanks for the additional information. I really appreciate it.
From your description, it sounds like he's got an injury or trauma to that eye, there's many ways that a puppy can injure an eye....either rubbing it on something outside, or even by rubbing it on the carpeting at home.
The fact that both the eyeball itself and the area around the eye are red and that it's only one eye (if it were both eyes, I'd be thinking about infection or other medical issues) makes me really feel like this is trauma of some kind.
If he were mine, I'd have him seen at the emergency vet tonight. If you're unsure of where one is in your area, you can go to: ***** ***** plug in your zip code. They'll show you where the closest one is to you.
At the vet, they'll likely want to use a special stain to check the surface of the eye for injury/damage and may want to use a tonometer to check the pressure in that eye. Once they determine what is going on they'll be able to send out the right medication to get the eye feeling more comfortable and help it heal.
Because this is an eye, I wouldn't wait to have her seen until your regular vet opens. Since it's already been going on for a day or so the possibility of the eye becoming too damaged to save increases the longer it goes without it being treated.
I hope this helps.