your dog is very young for it to be cataracts or something like that. So it won't hurt to have the vet take a look. And have him shut off the lights in the examining room when he checks with that thingamabob apparatus that the eye doctor uses on us!! I don't know what it's called!
But that is the best way for him/her to see what is going on! I'm shocked by how many vets don't do a proper eye check!! My dog is 8 so he has formed nuclear sclerosis, his iris is a bit cloudy..but my vet assures me that my dog doesn't even know its there...and i don't notice any issues with his eyesight. He can see me opening the fridge, cooking a mile away, he can see me rustling in the kitchen and he comes running!
hopefully this is something small, and simple and easily cured!
I found this article..quite interesting..
http://www.k911.biz/Petsafety/EyeProblems.htm