Leprosy is a very chronic and less contagious disease caused by Mycobacterium leprae. It mainly affects the skin and peripheral nerves, and in severe cases can cause disfigurement and limb deformity. The disease is widespread and mainly distributed in Southeast Asia. In addition to invading the skin and peripheral nerves to cause leprosy nodules, leprosy can also invade various organs and tissues in the body, and the eyes are the most commonly affected organs. 25% of patients can develop leprosy keratitis, in which patients not only lose the sense of touch, but also lose their vision. This is an irreversible double tragedy that brings great pain to patients and their families. The World Health Organization once proposed a grand plan to eliminate leprosy worldwide by the end of the 20th century. Although it has achieved quite remarkable results, leprosy is still an important public health issue. According to the latest statistics from the China Leprosy Association, there are less than 70,000 cases left in my country. At present, the incidence has dropped significantly. With the decrease in leprosy patients, better early diagnosis methods are needed. The treatment of leprosy and leprosy reactions is still far from ideal, and the effect of leprosy vaccines for high-risk groups still needs to be evaluated. Due to the high attention paid by the Chinese government to the prevention and treatment of leprosy, the planned goal of eliminating leprosy has been basically achieved at the end of the 20th century. Except for a few remaining patients in the western and remote mountainous areas, there are basically no new cases of infection in the country.