About John Loewenstein, MD

A practicing ophthalmologist for almost 40 years, Dr. John Loewenstein serves as Associate Clinical Chief and provides clinical care through the Retina Service at Mass. Eye and Ear. After earning his medical degree at the State University of New York at Buffalo School of Medicine, Dr. Loewenstein completed his ophthalmology residency at Boston University and a vitreoretinal disease fellowship through Boston University's affiliated hospitals.

His clinical practice focuses on diseases of the retina and vitreous, especially diabetic retinopathy, macular degeneration, and retinal degenerations. He worked with the Boston Retinal Implant Project to develop the surgical techniques for implantation of an experimental retinal prosthesis and performed the first surgical procedures to place a microfabricated electrode array on the retinal surface.

Departments, Centers, & Programs:

Clinical Interests:



Mass Eye and Ear Longwood
800 Huntington Avenue
Boston, MA 02215

Medical Education

  • MD, State University of New York at Buffalo
  • Residency, Boston Medical Center
  • Fellowship, Boston Medical Center

American Board Certifications

  • Ophthalmology, American Board of Ophthalmology

Accepted Insurance Plans

Note: This provider may accept more insurance plans than shown; please call the practice to find out if your plan is accepted.


Dr. Loewenstein's clinical practice focuses on diseases of the retina and vitreous. He conducts research in surgical education, leading the development of computer based cognitive simulations to teach cataract surgery and screening for retinopathy of prematurity. He led the development of a formal surgical curriculum for the Harvard Medical School Ophthalmology Residency Training Program, which significantly increased the number and quality of resident cataract surgeries.