Equine recurrent (periodic) uveitis (
moon blindness,
recurrent iridocyclitis) is an acute, nongranulomatous
inflammation of the
uveal tract of the
eye, occurring commonly in
horses of all breeds, worldwide. The causative factor is not known, but several pathogeneses have been suggested. It is the most common cause of blindness in horses. In some breeds, a genetic factor may be involved.