Copper's Bug Eye

As I have mentioned before, Copper's left eye seems to be popping out of his head (it isn't). The cancer behind it is growing, putting pressure on the eye, making it big. It became red yesterday, and I was afraid that he had burst a blood vessel. My vet said that that probably didn't happen, she said it is probably just the pressure building behind the eye making it look that way. He cannot see out of the eye, and Mr. Wiggins takes advantage of that by sneaking up on him on Copper's left side. I've tried to tell Mr. Wiggins that it isn't a nice thing to do, but he ignores me. If you ever give Copper a treat, you must make sure he can see it by approaching him on his right side.