To the right is the large Second Order lens from the Spectacle Reef lighthouse located in Northern Lake Huron. The lens is currently on display in Great Lakes Historical Society Museum in Vermilion, Ohio.

The Fresnel Lens - A parabolic type lens invented by French physicist Augustin Fresnel, commonly used in lighthouses throughout the world. Classified by size into six "orders" based on the lens focal length. The First Order is the largest at 12 feet tall with a diameter of 6 feet and a focal length of 36 inches. The Sixth Order is the smallest at 2 feet tall with a diameter of 1 foot and a focal length of 5.9 inches.

Photographer: Keith W. Churill