I am really puzzled. Last night when we covered Fiona up for bed she was perfectly fine. This morning when I went to give her fresh food and water I noticed that her left eye is closed. It's just closed. No outward signs of irritation (i.e.- it's not red, not swollen, etc) and she doesn't seem to be in any pain. She was functioning pretty normally aside from being a bit skittish when I approached on her "blind" side. She attacked her Avi-Cake and her poop is fine. She doesn't seem to be in any pain. Should I be worried? What could be causing this? Sometimes she gets feathers near/on her eyes but she seems totally unaffected by that, normally. Our 'keet likes to preen her head so he may have injured her, but they are in seperate cages so if that's the case the eye should have been closed last night while they were out playing.

Advice, anecdotes, and encouragement would be welcome!

ETA- I just called her vet and she said that it's most likely and irritation or eye infection of some kind. Since the other eye is fine and her nose isn't crusty she doesn't think it sounds indicative of some sort of bigger illness. She told me that if the eye is still shut when I get home from work I should probably take her to an emergency room to make sure it's not a tear, but if the eye if open she's most likely fine.