/an/

(Pic slightly related, rat here has a cataract...)

I think my rat has an orbital hematoma. I woke up this morning to discover she had one enlarged, red eye and her other eye was normal. The eye was slightly bulged, but looked normal around the outside. There was no open wound or discharge. It just looks like the rat equivalent of a human having a bloodshot eye. She's sleeping now, but she's active when I play with her. Should I be worried? Have any of you had rats with this before?

TL;Dr -- My rat's eye is red and enlarged, but there's no discharge or wound. Is this an orbital hematoma or something worse?