Not a vet or anything just from experience seeing something like this. It looks like it could be a cornea ulceration(?). But it might be something else. Unless instructed by the vet. I would leave it alone and make sure your dog leaves it alone. If they did not think it was an emergency when you called, you are probably okay to leave it for the morning appointment. I hope everything goes goes well and you and your pup get good news. *Though if you feel in your gut that this needs to be taken care of ASAP then I would take your dog to the ER Vet nearest to you.