Business US

‘Autofocus’ glasses can change their lenses in real time

Finnish eyewear company IXI is gearing up to launch smart glasses that look just like ordinary spectacles, but are able to “autofocus” based on the perceived needs of the wearer.

The glasses contain eye-tracking sensors as well as liquid crystals in the lenses, which are used to change the prescription instantaneously. The result, according to the company, is an improvement on current bifocal or varifocal lenses, both of which are meant for people who need assistance seeing both far and close distances, but come with drawbacks.

Bifocal lenses, whose invention is widely credited to Benjamin Franklin in the late 18th century, are split into two areas of different magnification, with the main area usually addressing long distance vision and a smaller cutout usually addressing reading or near vision.

A more recent upgrade to that classic design is the varifocal lens from the 1960s, which offers a similar solution but has a smooth, rather than abrupt, transition between the areas of magnification, aiming for a more seamless vision.

Both require the user to look through the correct part of the lens to focus on objects near or far, and while varifocals are credited with a smoother user experience, they also cause distortions in peripheral vision and require an adaptation period, on top of being several times more expensive than regular or bifocal lenses.

By using a dynamic lens, IXI does away with fixed magnification areas: “Modern varifocals have this narrow viewing channel because they’re mixing basically three different lenses,” said Niko Eiden, CEO of IXI. “There is far sight, intermediate and short distance, and you can’t seamlessly blend these lenses. So, there are areas of distortion, the sides of the lenses are quite useless for the user, and then you really have to manage which part of this viewing channel you’re looking at.”

The IXI glasses, Eiden said, will have a much larger “reading” area for close-up vision — although still not as large as the entire lens — and it will also be positioned “in a more optimal place,” based on the user’s standard eye exam. But the biggest plus, Eiden added, is that most of the time, the reading area simply disappears, leaving the main prescription for long distance on the entire lens.

“For seeing far, the difference is really striking, because with varifocals you have to look at the top part of the lens in order to see far. With ours, you have the full lens area to see far — as you were used to when you were slightly younger,” Eden explained, referring to people who had glasses for distance vision from their teens or early adulthood, before starting to also need reading glasses, like most people as they get older.

IXI has 75 employees and has raised just over $40 million funding. Its autofocus glasses will launch within the next year and will cost more than regular ones, Eiden said, without giving specifics: “We will be in the really high end of existing eyewear.”

The new glasses won’t come without drawbacks, Eiden admits: “This will be yet another product that you need to charge,” he said. Although the charging port is magnetic and cleverly hidden in the temple area, overnight charging will be required. However, the electronics and battery don’t have much of an impact on the appearance of the glasses, which could easily be mistaken for regular ones. They also weigh roughly the same, with one of the latest prototypes weighing just 22 grams (0.78 ounces).

Some visual distortions are also expected: “In our lens, of course, there is this blend area,” Eiden explained. “The center part is the sharp area, and then there is the edge where the liquid crystal stops and which is not that great to look into, but the center area is large enough that you can use that for reading. So, we do have our own distortions that we’re introducing, but the majority of the time, they will not be visible.”

Another limitation is that more testing is required to make the glasses safe for driving, Eiden said, adding that in case of a malfunction of the electronics or the liquid crystal area, the glasses are equipped with a failsafe mode that shuts them down to the base state of the main lens, which would usually be distance vision, without creating any visual disturbances.

The user’s eyes are tracked by an array of photodiodes — which convert light into electrical signals — and LEDs; together, they bounce invisible infrared light off the eyes and then measure the reflection, to infer what the user is looking at.

While IXI said it is designing the glasses for everyday use, which includes dealing with temperature changes, moisture and user movement, the company has yet to disclose under which specific conditions the glasses will be able to function optimally.

Ian Murray, a professor of visual neuroscience at the University of Manchester, in England, who’s not involved with IXI, said that in principle the autofocus glasses are an excellent idea, although initially they will have limited application and will be regarded as a novelty: “It is all perfectly feasible from a physics viewpoint,” he wrote in an email to CNN. He added that there are still questions left to answer, such as how wide the field of vision will really be and how the glasses will behave in low lighting conditions.

Other companies are also developing autofocus glasses that use liquid crystals to create an adaptive lens, including Japan’s Elcyo. Another Japanese company, ViXion, already sells autofocusing glasses, although they don’t look like normal glasses and the user must look through two small apertures to get the autofocus effect.

IXI’s glasses, which will be manufactured in Finland, will launch in Europe first, after the company has European regulatory approval, and it will later pursue FDA approval for US release, with the rest of the world to follow. Only “two or three” different shapes will be available at the beginning, but in different widths.

Eiden equates the arrival of autofocus glasses to the introduction of autofocus in cameras: “The eyewear industry hasn’t really been innovating for vision correction,” he said. “After varifocals, there has been basically nothing. That’s really what we want to change. Maybe 10, 15 years from now people will be wondering, how did we wear those fixed focus glasses in the old days?”

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