Dr O’Connor himself made substantial contributions to the field, with particular distinction in the area of ocular toxoplasmosis. His work, which clarified the relative roles of parasite proliferation and hypersensitivity reactions in the pathogenesis of recurrent ocular toxoplasmosis, has had a major effect on current treatment strategies. His research was funded by the National Eye Institute for his entire academic career and he received numerous distinguished awards for his academic contributions, including the Jackson Memorial Lectureship and the Mildred Weisenfeld Award for Excellence in Ophthalmology. He spent many years giving back to the ophthalmology community, serving on numerous National Institutes of Health study sections, the National Advisory Eye Council, and the Association for Research in Vision and Ophthalmology Board of Trustees. He also served on the editorial boards of Archives of Ophthalmology, American Journal of Ophthalmology, Investigative Ophthalmology and Visual Science, and Survey of Ophthalmology and as an examiner for the American Board of Ophthalmology.