As a new faculty member in 1957, Dr Campbell was appointed director of the Knapp Memorial Laboratory of Physiological Optics at the Edward S. Harkness Eye Institute, succeeding LeGrand Hardy, MD. The Knapp Memorial Laboratory of Physiological Optics, previously renowned for development of the Hardy-Rand-Rittler pseudoisochromatic plates for testing color vision, would soon become resurgent under the new leadership. By initiating a subspecialty retina clinic in 1958, Dr Campbell was able to combine clinical observations and laboratory investigations into a synthesis that culminated in his remarkable development of a prototypical ophthalmic ruby laser that, in his hands, proved to be an effective alternative to invasive surgery in a variety of blinding retinal diseases. Continuous refinement resulted in an affordable compact air-cooled instrument that ushered in the golden age of the laser in ophthalmology and subsequently in many other medical and surgical disciplines. Soon thereafter, Dr Campbell initiated a course at the American Academy of Ophthalmology with colleagues Robert Ellsworth, MD, and Harold Spalter, MD, to introduce the potential of laser therapy to ophthalmological practitioners and trainees worldwide.