Complex sentence: Phelps was one of thirteen founding members of the American Glaucoma Society, the first meeting of which, held in Iowa City on June 11-13,1987, was convened in his memory.
Split into simpler sentences: Phelps was one of thirteen founding members of the American Glaucoma Society. The society's first meeting, held in Iowa City on June 11-13,1987, was convened in his memory.