savannah moniter health problems

I have a savannah monitor that is about 5 years old. for the past 1 year and 3 months, I relied primarily on my dad to care for my monitor as I lived In the city next to the city my monitor lived in because I recently moved. I just have moved him to the city I live in now to discover that he seems to lost about half of his body weight, with a reduced size stomach and partial vision loss. I really want to see him get better. I plan to move him into our new houses backyard in the next 2-4 months. he is living in a 6x3x2. I know. small. but that's all I could afford. (it was free from my uncle) my dad kept on telling me he was feeding him eggs and I kept telling him to stop. please help me. he is eating but walks around with his eyes closed most of the time. he acts like he is on drugs. the thing I want to know most is is there any way to get his vision back? I know its bad because when I put my finger near his face, he wont close his eyes and I think its not gone because I tried shining a flashlight at him when he was sleeping and he opened them