Progressive retinal atrophy (PRA) and central progressive retinal atrophy (CPRA) are two degenerative eye disorders that lead to blindness. A veterinary ophthalmologist can determine whether your rottweiler has these or other eye diseases. CERF provides a registry for dogs intended for breeding. The CERF evaluation lasts for one year. Any rottweiler that you buy should have parents that are both registered with CERF. If you plan to breed your rottweiler, you will need to have its eyes examined and have it registered with CERF as well.
Eye diseases that can lead to blindness include glaucoma, juvenile cataracts, and progressive retinal atrophy. It is very hard to screen for these diseases in breeding dogs because they may appear without warning later in the dog's life. This is why CERF certification only lasts one year.