Dr. Foster received his Bachelor of Science Degree in Chemistry at Duke University, with Distinction and Phi Beta Kappa in 1965, and received his Doctor of Medicine Degree at Duke in 1969, being elected to Alpha Omega Alpha. He trained in Internal Medicine at Duke and at the National Institutes of Health and taught Internal Medicine, as Instructor in Medicine at the George Washington University. In 1972, Dr. Foster entered his Ophthalmology Residency training program at Washington University in St. Louis, and having completed that in 1975, he then traveled to Boston to do two additional Fellowship trainings in Cornea and External Diseases, and in Ocular Immunology. He was invited to join the full-time faculty of the Department of Ophthalmology of Harvard Medical School, where he was a member of the Cornea Service and Director of the Residency Training Program at the Massachusetts Eye and Ear Infirmary. He began his independent research in 1977, and was continuously funded by grants from the National Institutes of Health until1990.

He created the Ocular Immunology and Uveitis Service at the Massachusetts Eye and Ear Infirmary in 1980, and began the Uveitis and Ocular Immunology Fellowship in 1984. Over 100 Ophthalmologists have successfully completed this training program in uveitis and ocular immunology, and most have contributed to the over 1000 published papers, chapters, and books that Dr. Foster has authored. Dr. Foster continues to direct a research laboratory at the Massachusetts Eye Research and Surgery Institution (MERSI), through the support of his Foundation, The Ocular Immunology and Uveitis Foundation; this laboratory is devoted to the study of eye inflammation, surgery, and infections. Dr. Foster sees and treats patients with uveitis and all ocular inflammatory diseases from the front to the back of the eye, cornea and external ocular diseases, cataract, and glaucoma.