20/20

The remarkable technology of our human eyes cannot be replicated—at least, not yet

This piece has been updated.

No matter the state of your eyes, Gareth Webb promises you a better-than-perfect vision. All that is needed is a non-invasive surgery to replace your natural lens with a patented “bionic lens.” The new lens will not suffer from decay, which means you will never get cataract. The eight-minute, painless surgery is also safer and doesn’t come with the side-effects of laser surgery. And, according to Business Insider, “the quality of your vision will always be perfect, and it will not deteriorate over time.”

A marketing sell can’t get better than that. The trouble is that Ocumetics, Webb’s company, is going to struggle to live up to those promises. While the natural lens in a human eye has limitations, no artificial lens has been able to perform all its versatile functions so well.

“This is a much sought after goal and hits the news from time to time, but no designs to date can be considered successful,” James Wolffsohn, professor of optometry at Aston University, told Quartz.

Ocumetics has some major hurdles to clear to prove that it is any different—it has yet to test its technology in animals, a key step before conducting clinical trials in humans. (We’ve contacted the company for comment, and will update this post when we hear back.)

Eyes are one of the most delicate parts of the human body. And the physics and biology of how light is interpreted by your eye limits how far technology can go to replace natural functions of its parts.

eye_xsection_01

To see the world, light has to enter through the iris, cross the lens, and fall on the retina in just the right way. For all of this to work, every part has to do its job perfectly: the iris has to open and close to control how much light gets through, the lens has to focus the light to create a clear image of the real world inside the eye, the retina has to convert the image into electrical signals and send them to the brain, and all this has to happen while the shape of the eye remains static.

When any of this doesn’t work, people suffer from poor vision. Those with long-sightedness—a common problem among children—may have a problem with their lens or their eyeball may be too short. Those with short-sightedness—a more common problem among adults—mostly have the problem because their eyes become too long from front to back. In both cases, pair of glasses or contact lenses can fix the problem most of the time.

Super vision

Webb wants to do away with the slight inconvenience of external lenses. He has developed a lens that he claims can do all that a natural lens can do without its limitations.

This not a new idea. As you age, the natural lens deteriorates causing a cataract. Ophthalmologists routinely replace the faulty lens, mostly in old people, with a synthetic one.

Ocumetics bionic lens
Ocumetics bionic lens (Darryl Dyck/Canadian Press)

However, even with a replaced lens, the person has to wear a pair of reading glasses. This is because a synthetic lens cannot squeeze and adjust itself like a natural lens can with the help of ciliary muscles in the eye. Thus, the synthetic lens corrects for any short-sightedness but cannot fix age-related long-sightedness.

Ocumetics claims that its bionic lens is “accommodating,” which is to say that it can be squeezed like a natural lens. But Matthew Reilly, a biomedical engineer at the University of Texas at San Antonio, told Quartz that the only approved accommodating lens, called CrystaLens, has been found to not offer any accommodation. “There may be other approved designs outside the US and certainly there are many under development but, as far as I know, none of these have been shown to work in a living body,” he said.

And Webb’s claim that the lens will offer better than human vision—if you were able to barely see things 10 feet away then bionic lens will let you see things 30 feet away—is even more suspect. Wolffsohn, who looked at the patents, finds it a novel technology but he is unclear how it really works. “To provide better than normal vision you would need a telescopic lens combination, but this is at the expense of your field of view. This would not be a sensible approach,” he said.

Ocumetics hopes to show the world what’s really possible with a bionic lens by 2017. Beating the human eye’s natural lens for its versatility is going to be hard.

Update: This piece mistakenly stated that a synthetic lens corrects for long-sightedness. In fact, it corrects for short-sightedness.

home our picks popular latest obsessions search