TruFocals Use Liquid Lens for Adjustable-Focus Eyeglasses

By Stuart Fox Posted 08.04.2009 at 1:00 pm 9 Comments

Adjustable Lenses Michal Czerwonka via New York Times

In 1764, a cartoon showed Benjamin Franklin wearing the first pair of bifocals, and not a lot has changes since then. About 100 years after that, the first pair of adjustable focus glasses was patented in the United States, but it used different fixed-focus lenses. Now, 245 year after Franklin and 143 years after the first adjustable glasses patent, someone has actually developed adjustable lenses that work.

According to The New York Times, inventor Stephen Kurtin has developed the first manually adjustable lenses that let the wearer adjust from long distance to short distance viewing at the flip of a switch. The secret is a layer of liquid within the lens that changes shape depending on the situation.

Called TruFocals, the glasses are composed of two components, a rigid plastic or glass lens, and a clear liquid that also acts as a lens. A slider on the top of the frame's bridge compresses the liquid, changing the shape and focus of the liquid lens, and thus the distance of focus for the wearer.

There have been other adjustable lens glasses created before, including the winner of a PopSci Best of What’s New Award in 2000. But those lenses had adjustable prescriptions, and did not toggle between long and near vision for a single user.

The glasses retail for $895, but they are just the beginning. As soon as next year, a company called PixelOptics hopes to release glasses that perform the same function as TruFocals, but do so using an electric impulse that alters the refractive index of the lens. Looks like the adjustable glasses market just got a lot more crowded.

[via The New York Times]

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9 Comments

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ultimatenerd22

08/04/09 at 1:05 pm

liquid thats awesome. good thing i dont need glasses.
www.youtube.com/watch?v=H-PnT38bGvg

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rlb2

08/04/09 at 3:09 pm

When something new like this comes out there are other things that may be use for the product, although one may not be able to "see" it at first.

Imagine scaling this up to use for solar concentrators. You wouldn't need a tracking device for the concentrator...

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empjag

08/04/09 at 7:29 pm

Imagine an automatic shift from near to far with a sensor that can tell when a person squints. No manual switch, just do what comes naturally when your vision is impaired. Just throwin that out there.

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atalaya

08/04/09 at 9:11 pm

I went to the PixelOptics web site (PixelOptic.com) to see what it was all about.

My understanding is that it is theoretically possible to make an electronic lens that can increase or decrease ADD over some range on-demand. (Of course, then you have to figure out how to focus it, how to carry the battery power required etc.)

However, as I read the PixelOptics web site, this is NOT what they claim to have under development.

As I read the claims and deduce from the demo, what they are really working on is a progressive lens with the traditional distance, and medium fixed-focus zones. The difference is that the (fixed) ADD in the reading portion can be turned on and off at will. "On" will increase the diffraction (ADD) in the reading portion of the lens by a fixed amount. "Off" turns off the current and the extra reading ADD goes away. The amount of ADD does not vary. You cannot change the focus. And, based on the demo, the optical quality is not NEARLY good enough to be acceptable for a full frame variable focus lens.

As they say on their site:

"It means that you can have the ability to switch the reading portion of your lenses on and off whenever you want. Or, switch it to “automatic” mode and forget about it. You will have uninterrupted vision, just like your progressive lenses but with wider distance vision, wider intermediate vision, wider reading vision and half of the peripheral “swim” that most people experience while wearing a progressive lens."

So, basically a "better progressive lens" -- not a focusing lens.

If you check out PixelOptics then look at the Trufocals.com site, you will see that what TruFocals has is very different than what PixelOptics is working on.

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atalaya

08/04/09 at 9:14 pm

Oops sorry: a typo in the previous post.

The PixelOptics web site is, of course PixelOptics.com (That is Optics with an "s", not Optic without the "s")

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CasusUniversum

08/04/09 at 9:20 pm

Or better yet, you could imagine glasses that had a small sensor to detect where you were looking and maybe a small laser distance finder to determine where and when to focus...I guess that sounds pretty far fetched but one can dream.

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researchone23

08/05/09 at 3:06 am

An invention that helps people. Wonderful step up in that field. But I thought they had liquid prisms over 40 yrs ago. Think we'll see this technology in microscopes? Telescopes? Or in Rifle and bomb sights... Perhaps the use of a remote control to adjust the lens is another plus. Or save $900. and simply wear in-expensive throw away contacts with the cheater edge... Once they start making more- the $900. price tag may get reasonable for everyone who needs the exterior lens weight on their nose. The parts look too common for that outragious price.

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AdamCollet

08/10/09 at 6:46 pm

Or just get lasik

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