John Phay is a board-certified surgeon at the Ohio State University Medical Center. His practice focuses only on Endocrine Surgery which includes surgery of the thyroid, parathyroid, and adrenal glands. While on faculty at Vanderbilt University, he was part of the team which discovered that parathyroid glands have a natural auto-fluorescence which helps in their identification. He also demonstrated that the thoracic duct could be visualized in the neck with an injection of indocyanine green which may help prevent injury to this delicate structure during neck dissections for cancer.