Day Blindness in the Labrador Retriever and Labrador crosses is an autosomal recessive inherited diease. Thw condition, also known as Achromatopsia Type 1 (ACHM-Type 1) which is present at birth. Clinical symptoms become apparent at approximately 8-10 weeks of age. The disease causes the dogs to be unable to see in bright/daylight conditions. In lower light conditions, e.g. at night, Labradors with this disease have visual function comparable to normal dogs.