Weeks, John Elmer (1853–1949), American ophthalmologist. Weeks founded a clinical laboratory for ophthalmology which came to be known for its outstanding work in bacteriological and pathological studies. His personal accomplishments included the development of a method for using X-rays to locate foreign bodies in the eye, an operation for the surgical reconstruction of the orbit, methods for the surgical treatment of trachoma and glaucoma, and the invention of a new instrument for the extraction of cataracts. In 1886, independently of Robert Koch, he isolated the bacterium, now known as the Koch-Weeks bacillus, which causes an infectious form of conjunctivitis. He confirmed the identification by successfully inoculating one of his own eyes.