My cat has bloodshot eyes, but no other signs of eye infecti

  He had an eye infection about a month and a half ago, but I took him to the vet, she gave me ointment and it cleared up. I'm actually wondering if it's tied into his behavioral problems, because I notice it when he's gone psycho and is biting my hand. He's really split-personality, being super nice and cute and sweet one second, and a crazy monster the next. Any ideas?
He's smoking crack? Just kidding.

Take him to the vet.
No sleep

take to vet