The first Fresnel lens, installed in the elegant Cardovan Tower lighthouse on France's Gironde River in 1822, was visible to the horizon, more than 20 miles away. Sailors had long romanticized lighthouses. Now scientists could rhapsodize, too. "Nothing can be more beautiful than an entire apparatus for a fixed light," one engineer said of Fresnel's device. "I know of no work of art more beautifully creditable to the boldness, ardor, intelligence, and zeal of the artist."

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Fresnel worked out a number of formulas to calculate the way light changes direction, or refracts, while passing through glass prisms. Working with some of the most advanced glassmakers of the day, he produced a combination of prism shapes that together made up a lens. The Fresnel lighthouse lens used a large lamp at the focal plane as its light source. It also contained a central panel of magnifying glasses surrounded above and below by concentric rings of prisms and mirrors, all angled to gather light, intensify it and project it outward.

State of the art, one of the seven wonders of the Ancient World, the great lighthouse of Alexandria, built around 280 B.C., towered some 450 feet above Egypt's greatest harbor. At that height, it was the second tallest structure in the world, after another of the seven — the Great Pyramid of Giza. The light within, also state of the art, was an open flame.

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Jesse Schell, a professor at Carnegie Mellon University’s Entertainment Technology Center and CEO of Schell Games, says the technology does sound potentially useful for virtual reality. How well it could work and how practical it could be, though, is harder to say.

While the technology is not entirely new—it’s been used in smartphone camera lenses in the past, for instance—Deep Optics claims to be able to use it in lenses that are larger and more optically powerful.

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Fresnel lenses soon shone along the ragged coastlines of Europe, but surprisingly, America was slower to see the light. As mariners came to depend on Europe's powerful new lights, they complained bitterly about the puny lamps lighting America's coasts. Despite the clear superiority of Fresnel lenses, the parsimonious bureaucrat in charge of federal lighthouses, Stephen Pleasanton, considered the cost prohibitive. Finally, the uproar became so great that in 1838 Congress launched an investigation. It was not until then that Congress coughed up the cash to import a few Fresnel lenses. The first were installed in 1841 inside the two towers at Navesink Lighthouse, overlooking the approach to New York Harbor.

From that time until the 18th century, the lights that warned ships that they were approaching land improved hardly at all. Some burned coal. Others stuck with wood. Oil lamps backed by mirrors eventually offered a bit more candlepower. Still, every coastline in the world remained littered with the ribs of broken ships whose captains didn't see the lighthouse until it was too late. Then, in 1822, a frail scientist with a passion for optics made a revolutionary breakthrough. His name was Augustin Jean Fresnel.

You won’t be able to buy glasses that include this technology any time soon. While the company has the basics of a working prototype, including functional lenses and other components, it still has a lot of work to do when it comes to perfecting the lenses and the system for detecting pupil distance, Haddad says, not to mention figuring out how to shrink everything down so it can fit into something as slim as a pair of eyeglasses. He expects that it will be two years before Deep Optics will start having people test the glasses extensively.

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Haddad says the Deep Optics technology may be useful for other things besides vision problems. For example, it may offer a way to focus your eyes more naturally when wearing a virtual-reality headset. The experience requires you to focus both on a flat display ahead of you and on 3-D images that look closer to your eyes, which makes some people feel sick. Haddad thinks the constantly adjusting lenses can help.

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As a child, he was a slow learner who showed little interest in language studies or in tests of memory. By the age of 8, he could barely read. Yet his boyhood friends, for whom he studiously determined how to increase the power of popguns and bows, called him "the genius." When applied to optics, his genius proved to be real and considerable. Where others had improved existing lighthouse technology, Fresnel leapt forward by studying the behavior of light itself. His studies both advanced the understanding of the nature of light and produced the most important breakthrough in lighthouse lights in 2,000 years.

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For thousands of years, lighthouses created their lights with open flames which, naturally, were ineffective during high winds or rain. Then, in the 1690s, the glass lantern room was invented and first installed in England's Eddystone Lighthouse. Candles placed in the lantern room's glass lantern burned more brightly and securely than the earlier open fires. Another improvement came when pieces of mirrors placed in huge, round, wooden bowls served as crude reflectors that helped to direct the light. But throughout the 18th century, as maritime traffic increased, shipwrecks multiplied. The search was under way for a stronger, more reliable light.

There is some controversy over who first placed parabolic mirrors behind flames to boost candlepower. L. Reynaud, an 18th-century chronicler and public works official, credited Swiss scientist Aimé Argand with the first installation of an apparatus using reflectors, in 1783. Argand also invented, in the 1780s, a long-burning smokeless oil lamp that removed the necessity of stoking the flames all night. But the greatest innovation was to come from Augustin Fresnel.

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The company initially hopes its technology can be useful for people with presbyopia, which is a very common inability to focus close up as people reach their 40s and older. Typically, this is solved by wearing glasses with progressive lenses, which have different degrees of focusing power in different areas. Such specs limit a person’s field of view, though, Deep Optics cofounder and CEO Yariv Haddad argues, and force people to learn a new behavior to see clearly.

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As big as it seems, by lighthouse standards the Smithsonian glass beehive is just above average, measuring nearly six feet high and more than three feet wide. It was installed in the famous Bolivar Lighthouse overlooking Galveston, Texas, sometime around 1907. This lighthouse served as sentry, and for some as sanctuary, during the deadliest hurricane in American history. The lens is visible proof that unlike the sea, light can be mastered by human ingenuity.

With time, Galveston recovered. The Bolivar Light served the city until 1933, then was replaced by another light on the south side of Galveston. The museum's lens served through the Galveston hurricane of 1915, then retired with the lighthouse and was stored by the U.S. Department of the Interior until it was transferred to the Smithsonian in 1976. By then, Augustin Jean Fresnel, who lived only a short while after inventing his great device, had been dead for nearly a century and a half. Along with the lens, Fresnel left behind his theories of light, which form the basis of modern optics. Today, the principle behind the Fresnel lens is used in the headlights of cars and in the flashing lights on police and emergency vehicles. And in a few older lighthouses around the country, and the world, Fresnel's elegant beehives still shine.

The various reflector systems installed in lighthouses during the 40 years preceding the introduction of the Fresnel lens certainly had been improvements over the open fires or candles in lantern rooms. Still, they could trap only a small percentage of the light. All prior systems paled by comparison with the Fresnel lens.

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“The user doesn’t have to control it, doesn’t have to look through a specific area of the lens,” Haddad says. “[They] just have to look through the glasses as they would with any glasses prior to that.”

Called Deep Optics, the startup has spent the last three years building lenses with a see-through liquid-crystal layer that can change its refractive index—that is, the way light bends while passing through it—when subjected to an electrical current that depends on sensor data about where a wearer’s eyes are trying to focus. This month it announced it had brought in $4 million in venture capital to help make this happen; investors include Essilor, a French company that makes eyeglass lenses.

The idea behind Deep Optics, he says, is that when the glasses are not operating electrically, they’ll be focused on the far distance, like a normal pair of glasses. But when you’re looking at an object close up, like a book, or at an intermediate distance, like a computer display, sensors tracking the eyes will send data about the distance between your pupils to a tiny processor built into the glasses; the processor will calculate where you’re looking and adjust the focus up to three diopters, which Deep Optics says covers the same visual range as a pair of multifocal lenses.

An Israeli startup is making glasses with lenses that can automatically adjust their optical power in real time, which may be a boon to people with age-related trouble focusing on nearby objects and could also be helpful for making virtual reality less nauseating.

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Only after 1852, when the United States created a Lighthouse Board made up of eminent scientists and mariners, including Joseph Henry of the Smithsonian and Alexander Bache of the U.S. Coast Survey, did the great lenses really begin to light America's coastline. By the Civil War, nearly all lighthouses in the United States had Fresnel lenses. It was shortly after the Civil War, however, before a beehive of prisms first shone from the Bolivar Light watching over Galveston. A Fresnel lens, similar to the one on display at NMAH, was still in use there in September 1900, when waves from the Gulf of Mexico began pounding the coast.

Late in the morning of September 7, the U.S. Weather Station in Galveston learned by telegraph that a hurricane had just ripped across Florida and was somewhere over the Gulf. The next day, a telegrapher wired Washington, D.C. that Galveston was going under. Thousands died. Among the survivors were 125 people who found safety in the lighthouse. Keeper H. C. Claiborne exhausted a month's supply of food feeding the crowd. When the tower swayed in the wind, disabling the machinery that rotated the lens, Claiborne turned the lens by hand crank and kept the Bolivar Light shining through that terrible night.

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An example of his greatest creation, a large object that looks like a crystalline beehive, may be seen inside the Hall of American Maritime Enterprise at the National Museum of American History. It towers above the museum's displays of ship models and marine artifacts. This is the Fresnel lens, not one lens really, but numerous tiers of prisms. Lenses like this one turned simple flames into beams upon which sea captains could take their bearings, avoiding risk to their ships and to the lives of their passengers.