Trachoma is one of the oldest infectious diseases known and is the world’s leading cause of preventable blindness of infectious origin. Trachoma is caused by the bacterium Chlamydia trachomatis and is spread through direct personal contact, shared towels or clothes, flies, and other things that have come in contact with an infected person. Risk factors include water shortage, flies, poor hygiene conditions, and crowded households. When left untreated after years of repeated infections, the inside of the eyelid may be scarred so severely that the eyelid turns inward and the lashes rub on the eyeball, scarring the cornea. This can cause pain, permanent damage to the cornea, and irreversible blindness. Trachoma is prevalent in a majority of the poorest and most remote rural areas of Africa, Asia, Central and South America, Australia, and the Middle East, often affecting women and children.