AARP Hearing Center
The Fresnel Lens:
The heart of a lighthouse!
In the 1700 and 1800’s open water shipping was the lifeline of commerce – it was the only way to transport goods between the continents, but it wasn’t easy. Among the many difficulties was the problem of ships, and all of their precious cargo running aground and being smashed on unseen rocks.
This necessity brought about the creation and design of many lighthouses on the coastlines, which would let ocean navigators see when they were getting too close to dangerous outcrops. The issue was, the lights were essentially a large candle or oil lamp, and many times they were so dim that when the boat Captain saw the light, it was already too late. So scientists of the day searched for ways to focus and project the light much further.
French physicist and engineer Augustin-Jean Fresnel developed the multi-part Fresnel lens for use in lighthouses. His design allowed for the construction of lenses of large aperture and short focal length, without the mass and volume of material that would be required by a lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet. A Fresnel lens can also capture more oblique light from a light source, thus allowing the light from a lighthouse equipped with one, to be visible over greater distances.
Eagle Harbor Lighthouse in Michigan.
The Chicago Harbor Lighthouse was built in 1893 for the World's Columbian Exposition. It resides near the mouth of Chicago River in Illinois, US 🇺🇸
Esopus Meadows Lighthouse during sunset in Port Ewen, New York, USA.
Beautiful Cana Island Lighthouse.
I was able to climb this Door County, Wisconsin lighthouse a few years ago.
Florence Oregon, Lighthouse! Heceta Head Lighthouse is a working 19th-century lighthouse is now home to a B&B with 6 rooms offering scenic views.
We were able to walk the beach next to this lighthouse some years ago.
Point Abino Lighthouse , Lake Erie
Pigeon Point Lighthouse, West Coast, California, USA.
A.L.🗼🗼Donaghadee Lighthouse is a lighthouse in Donaghadee County Down, Northern Ireland. Donaghadee is probably best known for its lighthouse and harbour. There has been a haven for ships at Donaghadee (locally known colloquially as the 'Dee') for centuries, and there has also existed a harbour since at least the 17th century.
Constructed 1836
Moonrise at Nubble Lighthouse
Pointe aux Barques Lighthouse and Maritime Museum. Huron County, Michigan.
The current structure, built in 1857, is one of the oldest active
lighthouses in the state.
In 1849, Catherine Shook was appointed Michigan’s first female lighthouse keeper for this lighthouse.
Yaquina Head Lighthouse
Oregon, USA. Was able to visit this area a few years ago.
South East Lighthouse , Block Island , Rhode Island
The lighthouse at Grande-Anse, New Brunswick, Canada.
Large Lake Superior waves crash into the shoreline in front of Split Rock Lighthouse in Two Harbors, MN on 5/20/25. This day brought 50+mph winds and 9’+ waves to Minnesota’s north shore and the results did not disappoint!
Sunny morning at the beautifully restored Eagle Harbor Lighthouse Museum, MI on Lake Superior - Photo by GLLKA member Bruce Bowers
Portsmouth Harbor Lighthouse during sunrise in New Castle, New Hampshire, USA.
❤ Lion's (Faux) Lighthouse For Sight, Long Beach, California 2013
The Lion's Lighthouse for Sight was dedicated on December 2000. The 65 foot metal tower is a symbol of the Lion's fundraiser activities for the visually impaired. Owned by the U. S. Coastguard. The harbormaster's office is at the base of the tower. 2000. Active (privately maintained and unofficial); focal plane 105 ft (32 m); continuous white light. 65 ft (20 m) steel tower with harbor master's office in the base. Lighthouse painted white, gallery black, lantern red. 40% of the funding for the lighthouse was raised by the Long Beach Downtown Lions Club, and the lighthouse is known as the Lions Lighthouse for Sight. The lighthouse was dedicated on 10 December 2000. It's called the Rainbow Lighthouse because it is floodlit at night in varying colors. Located just to the east of the Aquarium of the Pacific on the north side of the entrance to Long Beach harbor and the west side of the small boat basin.
New Presque Isle Lighthouse. Presque Isle, Michigan, Lake Huron.
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