It is not fatal, and only a small percentage will have detached retinas and be blind. The rest may have some loss of vision, but can still function quite well. What happens then is that the genes which express the severity of the disease come into play. There will be more and more retinal failures resulting in blindness. At some point, the central breeding emphasis will shift from good working ability to good eyes .
Detection is important.
The American Border Collie Association, Inc., has offered or subsidized eye examination clinics at sheepdog trials since 1996. It is also the principal donor to a CEA genetic research project of Dr. Gregory Acland at the James A. Baker Institute for Animal Health, Cornell University. Required eye examinations of all dogs entered in the National Finals has also raised awareness of the disease. You can see the weaknesses in this program. It is in everyone s interest to expand the eye examination coverage to all breeding pairs.