Weird clots in eye and other health conditions

Hello! I’m a newbie rat owner and I was hoping to have some help with my little man, nacho. I had adopted him from this family who didn’t really play with him anymore. He used to have a playmate but I was told she passed a while back. I got him alone and he has been doing perfectly fine for a while until the last few months.

He’s in his older days ( I got him when he was 3 to 4 months-ish.) I hadn’t known much about rats and heavily relied on google to care for him. He was doing amazing for a while! I got him a new cage that was big so he could have plenty of room and let him run around my room every once in a while.

We also have a hamster so we just use that brand of food for him as well and gave him a fair share of snacks, I made sure I knew what we shouldn’t give him. But the winter came along this year and he hasn’t been doing so good.

At first it started with him randomly being lopsided and tipsy turney. He would fall down his cage a lot and flip over onto his side for almost 4 days. I cushioned the bottom of his cage to keep him from falling hard and it seemed to work.

But I think he ended up becoming blind and deaf due to it. I made sure he had plenty of food and water and he still has the will to drink water and eat. He was able to get back into good health but just today I found out something bad was happening to his eye. Last night he was sneezing a lot and seemed really stressed, it was 1 AM and I tried to get him to drink some water. Other than that I hadn’t spotted signs of his eye before that.

He calmed a little and I went to bed. But in the middle of the day today I saw that his eye was super cloudy and had a bunch of red clots in it. I have a feeling that is overproduction of Posyphorin (sorry if I butchered the spelling) from research but I wanted to ask here. I didn’t know when it happened so I’m not sure if it had been developing for a while. He also regressed into his previous condition before Christmas.

He let me pet him and I tried to clean it with a cloth but he kept pushing me away and gently squeaking in pain so I stopped. I didn’t want to freak him out. I don’t know what to do. I highly doubt my mom will take him to the vet for this since she already assumed he was dying. Would anyone here at least know what’s going on with him?

Here’s a picture of his eye.