Is a foreign body sensation in the eye, like sand grinding, trachoma? No, it is not. Trachoma is also not caused by outdoor sand, but is a relatively common chronic infectious conjunctivitis caused by Chlamydia trachomatis, which is named “trachoma” because of its ability to form a rough and uneven appearance on the inner surface of the eyelids, resembling grains of sand. With the rapid development of our economy, the improvement of people’s living standards and sanitary conditions, the incidence of trachoma has now been greatly reduced. Early trachoma can cause varying degrees of eye discomfort such as tearing, itchy eyes, foreign body sensation and increased secretions. In the late stage, the eyelashes can grow inward to form an inverted eyelash, and the eyelashes continuously rub against the black eye to make it white, which seriously affects the vision.