My parakeet's head has become very red and eyes seem 'beady'?

Just some background. Last thursday, my cat knocked the cage over and attacked my bird. I took him/her to the animal hospital and they said he/she seemed fine, but they were concerned by the possible danger of shock. He/she lost some feathers and had a really raw looking wound on his/her back. Since I had to work that evening, I let the vet's take care of him/her and provide antibiotics. I noticed a few days ago that his/her head was turning a little reddish. I went home for christmas for about 3 days and I only now got back home for the first time. His/her head is now very red and his/her eyes are very beady and tiny and keeps trying to squint. Now this could be because I had them covered the whole time to keep them warm, but I am very concerned. After worrying, then being relieved, of possibly loosing him/her, I do not want to do that again. If anyone knows anything that can help me, please let me know. I don't want to lose him/her.

If the 'keet had antibiotics, it could be having a reaction to them. redness/swelling are VERY COMMON reactions to antibiotics. Is the parakeet kept in the sunshine? Sunshine reacts with antibiotics sometimes to produce these symptoms. I suggest you keep him/her out of the sun, and if you go back to a vet, find one that specializes on birds and exotics.

you need to take him back to the vet. Sounds like head trauma, but can be a whole host of different things. Birds do not show signs of illness until they are much sicker than they appear. Flock mentality

the redness might be a symptom of the antibiotics. since you had the cage covered for a long time. it might be that the light is bothering your bird. i dont think there is anything wrong with your bird, but to be on the safe side, i would take him/her to the vet.
i hope your bird gets better, and clean his/her cage well(an infection in the wound that your bird has on the back might be fatal).

and try to keep the bird away from the cat. i hava 4 parakeets and a cat and its happened before. hang the cage to the wall where the cat can't reach it.^-^