A veterinary ophthalmologist is a veterinarian who specialized in the diagnosis and treatment of animal eye diseases, and who is board certified by the American College of Veterinary Ophthalmologists (ACVO). The ACVO is an American Veterinary Medicine Association specialty board, an association which sets the standards for advanced professionalism in veterinary ophthalmology. There are currently about 270 ACVO board certified specialists world-wide. Following 8 years of college and veterinary school, these individuals usually complete a one-year internship before they serve in a 2-3 year residency in comparative ophthalmology at a veterinary teaching hospital under the guidance of senior ophthalmologists. In order to be elegible to sit for the board examination at the end of the residency, a "credential package" consisting of publications, case reports and resume has to be accepted by the ACVO exam committee. If accepted, the candidate is allowed to take the 4 day examination consisting of written, practical and surgical parts. Upon successful completion of this examination, the veterinarian is recognized as a Diplomate ACVO (DACVO) or board-certified in veterinary ophthalmology.