Cockatiel with respiratory problems..

I found my cockatiel laying on the floor three days ago , and we took him to the vet .. The doctor said he has bad respiratoy problems , he gave us some anti biotics that might help . Its been two days now and he still cant breathe well .. He can't stand on his left leg so we have to be so careful when we carry him ... He also sleeps all the time .. Yesterday he didn't eat anything but today he ate some seeds..
My question is ,, why is the eye of a cockatiel like this ??

Yesterday all day my cockatiel had one eye blinking normal and the other one was open , we tried to close his eye but he didn't want to close it .. His open eye was "Teary and reddish" .. I also noticed hair loss around the eyes few months ago but didnt think it was a problem. Please help me :(!!!