Dr. John Mark de Leon has a special interest for visual fields and imaging in glaucoma. He is an avid educator and a heart for glaucoma research. He finished is medical education at the University of the Philippines and his residency in ophthalmology at the Cardinal Santos Medical Center both in Metro Manila. He completed glaucoma clinical research fellowships at the Massachusetts Eye and Ear Infirmary, Boston, the Singapore Eye Research Institute, and at the Jules Stein Eye Institute, University of California, Los Angeles.