Doctors & Staff
Meet the experienced and friendly doctors and staff who make Peak Eye Care a proud provider of vision care products and services in Greenfield.
Mark Dagenais, O.D.
Dr. Dagenais is a 1998 graduate of Illinois College of Optometry. He has spent 34 years in eye care, beginning as an ophthalmic technician in the US Air Force, both in the clinic and in the operating room. He also worked for the Eye Bank in Chicago procuring donor tissue. Dr. Dagenais was a founding partner and administrator of the Eye Group, S.C., where he practiced for 20 years. He is a skilled practitioner, excelling in fitting contact lenses, including specialty lenses: corneal, corneal-scleral and full scleral lens types. His passion is helping patients achieve the greatest vision possible.
Outside of his private practice, Dr. Dagenais proudly serves in the Air National Guard as an optometrist. His long history of service includes time in the Army Reserves and active duty US Air Force, to which he was reactivated during Desert Storm. One of the most rewarding annual training experiences he had was providing eye care to Guatemalan citizens.
Lake Country has been home for Dr. Dagenais for more than 25 years. He and his wife have two adult children, an English Lab, and two cats. Dr. Dagenais has a deep connection to the outdoors, participating in bird hunting, hiking, biking, fishing, and camping. He has hiked many National Parks, and he loves hearing about his patients’ adventures as well. His outdoor passions contributed to the name, Peak Eye Care.
Kristin Brennan, O.D.
Dr. Brennan received her undergraduate degree in Mathematics from the University of Rochester, N.Y. She went on to complete her Doctor of Optometry degree from The New England College of Optometry in Boston, MA. Afterwards she completed a primary care/ocular disease residency at the VA Boston Healthcare System- Brockton campus. Dr. Brennan has worked in various clinical settings, but most notably spending 12 years working at the VA hospital in Reno, NV. She has a strong interest in comprehensive eye care and the medical management of ocular disease. Dr. Brennan joined The Eye Group in September of 2019.
Originally from upstate New York, Dr. Brennan resides in Brookfield with her husband and 2 young children. In her free time she enjoys spending time with her family, hiking, biking, and exploring all the outdoor activities that Wisconsin has to offer. Dr. Brennan is a member of the American Optometric Association as well as the Wisconsin Optometric Association.