Dog’s eye is squinting and red, I’m going to the only available vet tonight but what can I do in the meantime?

My dog’s eye is squinting, red and has some discharge. She doesn’t seem to be scratching it but I know how serious eye problems are for dogs. The only vet available has an open appointment for tonight and emergency vets are extremely out of my budget so I have no choice but to wait. I know time is detrimental to eye issues so I want to know what to do in the meantime at home so it doesn’t get worse like a saline wash or something.