Shopping? Check out our latest product comparisons

Eyejusters - self-adjustable glasses designed for the developing world


May 30, 2012

The Eyejusters adjustable glasses with the adjustment tool in place

The Eyejusters adjustable glasses with the adjustment tool in place

Image Gallery (9 images)

Anyone who currently wears glasses or contact lenses will have likely consulted an optometrist to determine their prescription ... that is, if they live in the developed world. In developing nations, many people aren't afforded the opportunity to see a professional in this field. Thankfully there are alternatives, one of which are the self-adjustable glasses from Eyejusters.

The British company is aiming to take low-cost, self-adjustable glasses to developing nations. In order to do so, the team of four have developed an adjustable lens technology called SlideLens. This consists of a pair of lenses which act together to correct an individual's eyesight. By sliding one of the lenses over the other from left to right, the prescription changes until the world comes into focus.

There are two different types of SlideLens - positive power (for long-sightedness) and negative power (for short-sightedness). The range of the positive power lenses is from +4.5 to 0 diopters, while the range of the negative power lenses is from 0 to -5.0 diopters. This covers the majority of common cases. The glasses are priced at US$39.95 for the individual buyer, but the main aim is to distribute these to people in the developing world.

A pair of Eyejusters glasses being worn in Malawi

A pair of Eyejusters glasses being worn in Malawi

No professionals are required in the process of distribution, with anyone who has received basic training able to get involved. After a simple reading test, the type of glasses required by each individual patient is determined. They then choose which color they want, and can adjust the lenses until they're happy. A repeated reading test ensures an overall improvement in the patient's eyesight. The whole process can be seen in the video embedded at the bottom of the page.

Alternative Solutions

These aren't the first self-adjustable glasses ever conceived, with the Adaptive Eyecare spectacles developed by Professor Joshua Silver already on the market. Previous attempts have used fluid-filled lenses to solve the problem, but I personally feel turning a screw to adjust the prescription is a more elegant solution than spectacles adjusted using syringes and tubes. The Eyejusters also look less cumbersome and more stylish, although they wouldn't be many people's first choice of frames. This is function over form, and they do the job they need to do.

Regardless of the method used, this is definitely a problem in need of a solution. There are estimated to be 670 million people around the world living without the glasses they need, with 95 percent of the people in sub-Saharan Africa who need them going without. This is due to there being an average of one optometrist per one million people in that part of the world, compared to one per 10,000 in the United States and Europe ... which is a frankly shocking statistic.

Source: Eyejusters via RedFerret

About the Author
Dave Parrack Dave is a technology journalist with a ravenous appetite for gadgets, gizmos, and gubbins. He's based in the U.K., and from his center of operations writes about all facets of modern and future technology. He has learned more in his five years writing for the Web than he did in 11 years at school, and with none of the boring subjects thrown in to the mix.   All articles by Dave Parrack

Fantastic idea but I couldn't help but think of the Optigrab device from The Jerk.

30th May, 2012 @ 08:32 pm PDT

It would be fairly simple to integrate an unobtrusive slider and eliminate the screw, solving the aesthetics dilemma.

31st May, 2012 @ 05:36 am PDT

Heavy frames with adhesive tape move over; there's new geek glasses in town!

Shawn H Corey
31st May, 2012 @ 06:03 am PDT

Per Thier FAQ:

"... Recent research has also shown that individuals with low-to-moderate levels of astigmatism can also achieve a good improvement in their vision after performing self-refraction with adjustable glasses. However individuals with high levels of astigmatism still require custom-made prescription lenses. ..."

So, not for everyone. Astigmatism is not too hard to check. A pattern of, uniform width, evenly spaced (all angles between lines the same angle, like every 10 or 15 degrees) lines through a point could be looked at. If all lines are uniformly sharp - then no astigmatism. If corrected for near or far sightedness which these glasses do, and lines along one particular direction are much fuzzier than lines of other directions then you have astigmatism, which varies in severity and direction from person to person.

Great fun to drag the lens in the web page illustration though.

If you are over 40 and don't wear glasses for astigmatism, I think these would be great:

pass cursor over "Where to Buy" may be USA only at this time.

Then "click her to buy" - $40.

Diopter strengths range from 0 to 4.5x

*** Adjustment dials are removable and can be re-attached ***


"Adjustable Readers - Due to the popularity of this item, it is temporarily out of stock. Expected to ship within 6 weeks."

Also you can enter email address for updates on "adjustable reader" or "developing world".


Dave B13
31st May, 2012 @ 09:03 am PDT

At $39.95, they're more pricey than regular reading glasses that you can get at the pharmacy.

Victor Engel
31st May, 2012 @ 09:23 am PDT

At $40, these will be a life changer for a lot of people. Good for them.

Thomas Roberts
31st May, 2012 @ 09:44 am PDT

Victor, my guess is that you don't wear glasses. Reading glasses are not regular glasses. I am near-sighted. Reading glasses don't do a thing for that. I can't pickup a set of specs without getting a doctor's visit and a prescription.

Reading glasses are all + numbers. Near-sighted prescriptions are all - numbers.

Personally, I don't see why there aren't booths for emergency specs. Walk in the booth. Dial the lenses until they focus for you, and the 3D printer makes you a set. Pay the cashier.

31st May, 2012 @ 11:50 am PDT

My vision changes during the day, don't know why (nor do docs) so I would love these.

Fred Borman
31st May, 2012 @ 11:53 am PDT

Cheap reading glasses are the same in both eyes. Many people, like me, have different prescriptions for each eye. I just ordered a pair, waiting 6 weeks...

Fred Borman
31st May, 2012 @ 12:17 pm PDT

@ Victor E., You are absolutely correct.

The benefit of these is that they are adjustable, and they adjust for each eye.

The pharmacy reading glasses are fixed strengths and they are fixed at the same diopter for both eyes. I have too much astigmatism for non-prescription reading glasses including the eyejusters. The strongest clip-on reading glasses I've come across as commonly available are 3.0x.


Are may favorite of all the hood magnifiers, comes with second flop down lens inside and external loop can me moved to dominant eye, providing several strengths.

You need to be closer to what you are looking at with increasing strengths of simple lenses. Also they are cheaper than drugstore reading glasses. Don't bother with the included lights, remove them.

Dave B13
31st May, 2012 @ 12:24 pm PDT

Victor, there aren't the professionals available to ensure people get the right prescriptions though. So it's either adjustable lenses or send every prescription over until they find they right one. Which isn't at all practical.

Dave Parrack
31st May, 2012 @ 03:04 pm PDT


There's no "aesthetics dilemma." The knob is part of an adjustment tool. Once properly adjusted, the tool is removed, which also protects the lenses from being accidentally moved.

31st May, 2012 @ 04:37 pm PDT

They're better looking than the any shape you want as long as it's tiny and round Superfocus glasses.

Gregg Eshelman
31st May, 2012 @ 05:00 pm PDT

I want the hawkeye from legend of zelda.

31st May, 2012 @ 09:39 pm PDT

There is an additional benefit and business model change possible here in that once the wearer finds the best fit those numbers can then be used to mailorder glasses in a wide range of styles and at a price the 3rd world can afford. In one step the style, access, and cost challenges can be reduced to an achievable level. Still, in a part of the world where $40.00 is close to an annual income the 1st world will need to help.

1st June, 2012 @ 10:04 am PDT

@ Dave 13

The dial is going to break, changing it to a metal screw flush with the frame would be better.

Could not the dial also have the current neg & pos diopter set in the dial so a set of fixed diopter glasses could me made from a prescription based on the reading. The likelyhood is that those glasses are cheap, ones from locally sourced materials in Africa are cheaper still.

Currently glasses are sold on the internet & across the counter for £5 or less in the UK. The average income in Malawi in 2005 was $160 a year ( one pair of these glasses would be as much as the poorest could afford in a year, yet a pair of fixed diopter mass produced glasses costs 5 times less than the $39.95 quoted.

1st June, 2012 @ 12:51 pm PDT

I had been eagerly waiting a couple weeks since I ordered these for $40 and I just got my Eyejusters. It is definitely cool to be able to adjust them and I got them for working at my electronics workbench where you are working between arms length and then real close up soldering or assembling small stuff with a need to repeatedly adjust between those extremes. I have not really tried a long session of that yet. But the clear field of view is noticeably narrow compared to the readers that I have been using for working at computer or for reading. The Eyejusters have a sweet spot with about 30 degrees field of view horizontally that is pretty sharp in the center and then going further off axis, more and more distortion and defocus sets in. Vertically I see ~20 degrees field of view before noticeable distortion.. This is with a setting of ~ +2. With my 30" (diagonal) 2500x1600 high res monitor at ~30" viewing distance the edges (last 3-4 inches on each side) are unreadable. It will be a cool item to wear (with knobs attached!) to a geek events like robotics competitons. Hopefully they can improve these, but knowing what I know about optics, I am not going to hold my breath. I can see the value in distributing these to kids in 3rd world countries with no other option but I wonder if the adjustable glasses from Superfocus or from Pixeloptics have solved the field of view and clarity issue.

Frank N
21st December, 2012 @ 11:36 am PST
Post a Comment

Login with your gizmag account:

Or Login with Facebook:

Related Articles
Looking for something? Search our 28,280 articles