Dr. Cai Bing from the Department of Plastic Surgery of the Second People's Hospital of Guangdong Province introduced that nevus OTA is a hamartoma of dermal melanocytes, which often involves the gray-blue patchy damage of the first and second branches of facial trigeminal nerve and ipsilateral sclera. It is most common in periorbital region, zygomatic region, nose, forehead and zygomatic region. Half of the patients have blue-brown spots on their eyeballs, especially on a sclera, and the conjunctiva may also have pigmentation, which is a kind of birthmark. The etiology is unknown, and it may come from the embryonic period. Most patients exist after birth, and some patients begin to get sick several years after birth. Only a few patients get sick after trauma. At present, the most stable and ideal treatment for nevus of OTA is laser treatment.