Coats disease is a type of fundus retinal disease, also known as retinal capillary dilation. The etiology of coats disease is still unclear, but it occurs in healthy boys, mostly before the age of 10, and most often involves one eye. Because of the lack of obvious symptoms and the inability of infants and children to describe the disease in words, infants and children are often seen by their parents for strabismus and leukocoria (whitening of the lens, a type of cataract); school-age children are often seen for low vision in one eye during vision examinations. The disease progresses slowly, with a gradual loss of vision in the early stages until a sudden and significant loss of vision. When patients visit the clinic, most of the fundus changes are already advanced. During funduscopic examination, the retinal vessels are found to be significantly distorted, irregularly cystic dilated or beaded, and the retinal lesions are dotted or lamellar hemorrhages, which may be accompanied by neovascular membranes. There are yellowish-white lipid exudates in the deep retinal and subretinal layers of the lesioned area, which are deposited in sheets under the retina or distributed in a ring around the lesioned vessels. A stellate or ring-shaped hard exudate may be present when the macula is involved. In severe cases, it may lead to iridocyclitis, neovascular glaucoma, complicating cataracts, and eventually ocular atrophy. In summary, coats disease is a serious retinal lesion, which requires laser photocoagulation or condensation treatment in the early stage, and vitreous surgery is effective when exudative retinal detachment occurs.