Sclera Sclera The sclera, also known as the white of the eye, is the opaque, fibrous, protective, outer layer of the human eye containing mainly collagen and some elastic fiber. In humans, the whole sclera is white, contrasting with the coloured iris, but in other mammals the visible part of the sclera matches the colour of the iris, so the white part does not normally show. In the development of the embryo, the sclera is derived from the neural crest. In children, it is thinner and shows some of the underlying pigment, appearing slightly blue. In the elderly, fatty deposits on
Collie eye anomaly affected, a carrier, or clear, and is therefore a useful tool in determining a particular dog's suitability for breeding. Collie eye anomaly Collie eye anomaly (CEA) is a congenital, inherited, bilateral eye disease of dogs, which affects the retina, choroid, and sclera. It can be a mild disease or cause blindness. CEA is caused by a simple autosomal recessive gene defect. There is no treatment. It is known to occur in Scotch Collies (smooth and rough collies), Shetland Sheepdogs, Australian Shepherds, Border Collies, Lancashire Heelers, and Nova Scotia Duck Tolling Retrievers. Frequency is high in Collies and Shetland Sheepdogs, and