Help! My friends Black Moor is blind I think

[TrooshPanda]

I was checking out my friends aquarium and I've gotta say it's not in the best of shape but the main thing is his Black Moor keeps running into stuff and since yesterday has had a swollen white eye, and is lethargic and doesn't move off the ground unless food is put out he just sits on the ground. Please help I am definitely not an expert so I can't say and he is worried about Bob.

[Colu]

What are water parameters ammonia nitirtes etc  it's possible he's suffering from Popeye when it affects both eye's it usually caused by a bacterial infections bought on by poor water quality or an underlying disease Frist check your water parameters just in case anything off then I do a course of kanaplex  if he's still eating you can add it to his food feeding a small amount twice a day for 7 days