Dr. Kirn, originally from Maine, attended Gould Academy in Bethel before continuing his studies at Boston College, where he obtained his Bachelor of Science. He earned his Doctor of Optometry at the New England College of Optometry and completed clinical rotations with honors at the New England Eye Institute in Boston, the Brooke Army Medical Center in San Antonio, and the Veterans Administration Hospital in Newington, Connecticut.

In practice since 1998, Dr. Kirn examines patients of all ages at both the Sanford and Kennebunk locations. He offers comprehensive medical exams which include glaucoma, diabetic, and dry eye treatment. Dr. Kirn is a Board Certified Optometrist and a member of the Maine Optometric Association and the American Optometric Association.

Dr. Kirn and his wife Jennifer live in Kennebunk with their children Virginia, Gavin, and Trevor. In his spare-time, Dr. Kirn enjoys golfing, skiing, and traveling with his family.