Hello, I'm Dr. Kara. I have over 20 years of experience as a veterinarian and I'd like to help with your concerns about Baller.
In young guinea pigs getting ill is often secondary to not getting enough vitamin C in their diet, poor or improper diet or very dirty or dusty bedding.
Given his eye discharge I do believe he may have a respiratory infection or an eye infection secondary to dusty bedding. A poor diet make his immune system weak which allows secondary infections to become a problem.
Baller should be eating mostly timothy hay and grass hay. That will keep his intestines moving normally, which is a big concern in a sick guinea pig. He should be fed a small amount of guinea pig pellets (not rabbit) twice daily.
Are you supplementing vitamin C? Guinea pigs require that and if not done that predisposes to a weak immune system as well as joint problems. I recommend 50mg to 100mg per day per pig.
Ideally bedding would be low irritant. Do not use any wood chips as they carry bacterial and fungal spores and are irritating if they get in the eye. I recommend newspapers or recycled paper pulp bedding. Bedding should be changed as often as possible, you can spot remove dirty bedding but it all should be changed completely once or twice weekly.
Ideally he would see a veterinarian to have a physical examination and possibly prescribe some eye antibiotic drops. Guinea pigs are a prey species and as such hide their illnesses well until they are quite sick. If you can tell he is slower than usual and see symptoms he is likely much sicker than he seems.
If you cannot have him seen today then keep him eating and quiet.
Put him in the bathroom so when someone runs a hot shower or bath he can breathe the steamy air which will soothe his airways.
You can flush his eyes with sterile saline two to three times a day and then apply Polysporin ointment. You can also apply artificial tears several times a day to keep his eyes hydrated and comfortable. This should be done for at least week. Polysporin has weak efficacy against many bacteria, and prescription drops work better but if you cannot have him seen then this is worth trying.
And have him looked at as soon as possible if his appetite fails or he is worsening. If you don't have a veterinarian for him here is a link to help find one: http://www.aracnet.com/cgi-usr/seagull/vetfinder.cgi
Here is an excellent link to a site that will give you tons of information to keep him healthy: http://www.guinealynx.info/index.html
Let me know if you have any further questions.