Do Dogs Have Good Eyesight?

I always supposed that dogs have good eyesight. However, maybe some of them have problems with their eyes just as humans do.

I also should tell you that I have seen dogs bark at very strange things for no reason that I could understand.

Maybe you can invent some way to test your dog's eyesight. Will it run to get a stick or ball that you throw? If it can do that, its eyesight must be OK. Or maybe you can think of some other trick.