
Try not to worry too much, vets can do amazing things these days, and your dog will no doubt be given pain killing drops in the eye. Once under anaesthetic at the vets he won't be aware of anything either. Last summer my then tiny little Papillon puppy (1 kg!) had one of his eyes PUNCTURED by a cat, and he was screaming and vomiting and in terrible pain. The vet put him under and stitched his inner eyelids across the surface over the eye (to allow it to heal and rest) and left that in place for about a month, and we had to give drops 6 times a day. As soon as it was done, he acted normal again -despite one eye being shut and wearing an e-collar. :) His eye healed perfectly and you'd never know anything had ever happened to it. It sounds like your dog may simply have a small scratch or ulcer on the surface, and that should be even easier to heal. I don't know what it is with my animals but we are always unlucky wih eyes, I have a cat who has had to have both of his eyes repaired as they ruptured, one of them twice, my Cavalier had a scratch on the eye surface once etc, but they always get through it much better than we think. Obviously staying at the vets isn't nice, but it won't be for long. :)