Pet rat question

Question
Hey my rat had an eye infection and now she is blind in that eye.  Why does she have a hard time aiming for her treat when I hand feed her a treat?  Why does she keep accidentally biting my finger?  Will she ever stop?

Answer
How was the infection treated that it left her blind? If she is blind and your hand feeding her, she will have a hard time knowing the difference between her treat and your finger so it may not stop the biting.  If she cant see what she is aiming for she cant help biting the wrong thing.

Anyhow, I am curious how she became blind from the eye infection.