Though vision-impairing eye problems are not widespread in our breed, there is an incidence of juvenile cataracts. While this disorder does not progress to cause vision impairment or blindness, researchers tell us that breeding affected dogs can and will lead to more serious manifestations of the disease down the line. A breeder screening his or her breeding stock for eye disorders and not breeding dogs with cataracts or other eye problems ensures that such disorders will not become entrenched in the breed.
The independent registry that screens dogs for ophthalmologic disorders is the Canine Eye Registration Foundation, or CERF. You can search this link for eye exams on the sire and dam. CERF exams are recommended regularly on dogs in active breeding programs.
As with thyroid, not all breeders choose to pay additional funds to have their results posted to the CERF registry, relying instead on the assessment given by the ophthalmologist performing the examination. Again, as with thyroid, a breeder should be able to discuss the outcome of this eye exam, and show you paperwork that demonstrates the dog in question has passed.