I have a dog eye question!

I have a dog eye question!

Yesterday I came home from work and Emma was all squinty.  Her extra eyelids were really red and up over the bottom part of her eyes - one worse than the other.  I smelled her face to see if I could smell anything unusual on her (like mace or anything else I didn't recognize), but she just smelled normal.  Shaun flushed her eyes with water last night and she looked fine this morning.  I was planning to take her to the vet today if she didn't look ok, but she did.  But now she doesn't.  She's all squinty and red-eyed again.

What is going on, and is there anything I can do?  Our vet is closed until Monday now.  I don't think it's an emergency because she's acting normal otherwise.  I'm thinking it might be an allergy or something she's getting into around the house, but I have no idea what it could be!  I just want her to feel ok.  She looks so pitiful.  None of the other animals are having this problem.