Sometimes puppies are born with one eye underdeveloped.
If you just got your "pup," I would have your vet examine him or her. If there is a congenital problem affecting the eye, you should get a report from the vet and bring this up with the breeder of the puppy. That would be for the benefit of you, as the purchaser, your dog and any future dogs the breeder might have. Microphthalmia, if that is what it is, is genetic.
I searched the forums here, and years ago a person made one post about their dog with this condition, posted pictures of their dog with microphthalmia and its littermate sister with normal eyes. But that was the one and only time they were here.
If you just got your "pup," I would have your vet examine him or her. If there is a congenital problem affecting the eye, you should get a report from the vet and bring this up with the breeder of the puppy. That would be for the benefit of you, as the purchaser, your dog and any future dogs the breeder might have. Microphthalmia, if that is what it is, is genetic.
I searched the forums here, and years ago a person made one post about their dog with this condition, posted pictures of their dog with microphthalmia and its littermate sister with normal eyes. But that was the one and only time they were here.