Collie Eye Anomaly is both a hereditary and congenital disorder which is seen with great frequency in the United States and Europe. In the United States, it is seen mostly in rough and smooth collies, and to a lesser extent in Shetland sheepdogs. It is associated with microphthalmos syndrome in collies and has been inadvertently selected for in the quest for certain "desirable" facial characteristics. It has been estimated that up to 97% of all collies are affected with at least one of the phenotypic expressions of CEA. Veterinarians in the United Kingdom have found that approximately 70% of the collie population is affected by CEA. It is fortunate, however, that detectable visual impairment is found in only 2-4% of the collies examined. The lesions now believed to be associated with CEA include choroidal hypoplasia, coloboma of the optic disk and/or sclera, and intraocular hemorrhage with or without secondary retinal detachment.