Chronic infection of the eyelid and cornea caused by a microorganism that is spread by contact with eye discharge from an infected sufferer. Flies can also transmit the bacteria. Over time, the eyelid becomes scarred and turns inward. The eyelashes begin to scrape the eyeball and cornea, which eventually causes visual impairment and blindness. Worldwide, 84 million people are affected by trachoma. Clean water and good hygiene can prevent trachoma, while antibiotics can treat it early on. Inward-turning eyelids can be corrected with simple surgery performed by a nurse. (Information supplied by ORBIS International.)