swollen/ scabbed eye?

by Christina
(Chula Vista, CA, USA)

My bird has been in a condition for at least 5 months. He is a Zebra finch and flies completly normal, like before he got a condition. He has a scab over his eye and when he accidently rubs it off it always scares me because I seen blood by his eye. Again, his condition is only in one eye. My question is: how do i make the scabbing stop coming after he rubs off the scab that was on before? how do i stop the bleeding when he takes off the scab as well? His eye is also watery when the scab comes off.