Meet the Doctors

Lenard H. Hammer, MD, FACS, FAAODoctor Hammer

Lenard H. Hammer, MD is a Board Certified Ophthalmologist and a Clinical Instructor at the Johns Hopkins School of Medicine. He is a Phi Beta Kappa graduate and a fellow of both the American College of Surgeons and the American Academy of Ophthalmology. He is an instructor at the John Hopkins Wilmer Ophthalmological Institute and has served as ophthalmology section chief at Montgomery General Hospital.

Dr. Hammer completed his ophthalmology residency and had the honor of serving as the chief resident at the Nassau County Medical Center/Northport Veterans Hospital. He was privileged to become the Retinal Fellow at the Washington Hospital Center where he gained expertise in Retinal Diseases. Dr. Hammer’s residency training focused on comprehensive ophthalmology with an emphasis of cataract surgery and glaucoma. His retinal fellowship enabled him to gain sub-specialty training in diabetic retinopathy and macular degeneration.

Dr. Hammer has had his own DNA sequenced by New Amsterdam Genomics. He is now working with them to help make treatment decisions based on his clinical findings and the patient’s own genetic makeup.

Dr. Hammer has served Montgomery and Howard Counties for 30 years and is the managing partner at the Medical Eye Center. He lives in Clarksville with his wife, Cheryl, with whom he has been married to for 37 years.

Gordon Lui, MD

Information Coming Soon

Doctor Lui

Scott Becker, MD

Information Coming Soon

Doctor Becker

Vanessa Lima, MDVanessa Lima, MD

Dr. Lima practices comprehensive ophthalmology for the entire family. She provides medical and routine exams. Her specialty is in plastic and reconstructive eyelid surgery. Dr. Lima’s expertise in eyelid disease allows her to treat problems such as drooping eyelids, eyelid cancer, and eyelid malposition. She also manages common eye problems such as glaucoma, dry eyes, cataracts, diabetic retinopathy, and macular degeneration. Dr. Lima screens for eye disorders associated with general medical problems such as thyroid disease, diabetes, autoimmune disorders, and sleep apnea.

A local Marylander, Dr. Lima finished medical school and ophthalmology residency at the University of Maryland School of Medicine, she completed a fellowship in Oculoplastics, Lacrimal, and Orbital Disease at the University of Adelaide in Australia. Dr. Lima served as Assistant Professor in Ophthalmology at the Johns Hopkins University Wilmer Eye Institute for several years. She then joined the Medical Eye Center in 2012. She has been a member of the American Academy of Ophthalmology throughout her career. She enjoys volunteering at medical missions abroad and has written numerous peer-reviewed publications in the field of ophthalmology and oculoplastics.

Cristina F. Rouiller, ODCristina F. Rouiller, OD

Dr. Rouiller has been practicing with the Medical Eye Center for over 15 years, serving Howard and Montgomery Counties. She specializes in comprehensive eye care of children and adults, with emphasis on hard-to-fit contact lenses (including disposable, toric/astigmatic, rigid gas permeable, and bifocal). She is therapeutically certified and co-manages LASIK patients. Dr. Rouiller lives in Howard County and enjoys spending time with her husband and two children.




Yiyun Zhou, MD, PhD, MBA
Comprehensive Ophthalmologist and Cataract SurgeonYiyun Zhou, MD, PhD, MBA

Dr. Zhou grew up in Shanghai, China, and studied nutrition at Shanghai Jiao Tong University. She then took an adventure to the United States to pursue her dream of becoming a doctor. Dr. Zhou received her medical degree from the State University of New York at Buffalo, graduating with the highest honors, and was inducted into the Alpha Omega Alpha medical society. During her time in medical school, Dr. Zhou discovered her love for ophthalmology and microscopic surgery. She completed her ophthalmology residency training at the University of Rochester Flaum Eye Institute, where she served as chief resident and received the Surgeon’s Knife Award. Dr. Zhou is excited to fulfill her dream of becoming an ophthalmologist and providing quality medical and surgical eye care to patients in Howard and Montgomery Counties!

Outside of work, Dr. Zhou enjoys a plant-based lifestyle and exploring the world with family and friends.