Frequently Asked Questions
Eyejusters contain SlideLens adjustable lenses. Each SlideLens is a pair of lenses with a special shape that you are able to see if you hold the lens on its side and reflect light from the surface. When these lenses are slid across each other (left-to-right), their combined shapes act as if they were one lens with a changing spherical surface. Click here for more details.
How do Eyejusters work?
The major issue with providing glasses in the developing world is that there are very few qualified professionals (optometrists) to do so. In sub-Saharan Africa, for example, there is an average of 1 optometrist for every million people (compared to around 1 in every 10,000 people in Europe or the United States), and 95% of people who need glasses do not have them. Eyejusters work by providing the sight test and glasses all in one, and can be distributed and dispensed by almost anyone with basic training, allowing far more people to access the glasses that they have always needed. This is not possible with normal eyeglasses.
Why not just use normal glasses?
Yes! A number of peer-reviewed studies have validated self-refraction, which is the method by which an individual adjusts the strength of an adjustable pair of glasses to correct their own vision. Most recently self-refraction has been shown to be reliable and effective technique for people aged 12 and over, with a recent World Bank-funded study validating its use with teenagers (see our Success page for more details). We recommend Eyejusters are used only by those aged 14 or over to make sure they fit.

In use, self-refraction has been found to be as accurate as other field refraction methods, such as the use of expensive and bulky automated instruments (autorefractors), and is close to the gold standard of refractive eyecare, subjective-refraction by an experienced optometrist.

Does adjusting your own lenses work?
You can order a pair of Eyejusters by visiting our online store. If you choose to include an extra donation with your purchase, we'll also send a pair of Eyejusters to a vision project in the developing world that's working to bring clear vision to those who need it.

If you're looking to make a bulk purchase for the developing world, please have a look at our distribution kits or contact us.

Can I buy a pair?
Eyejusters are designed to work for most of the same conditions that normal eyeglasses work for - myopia (short-sightedness), hyperopia (long-sightedness) and presbyopia (loss of near vision performance, usually due to aging). 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.

Eyejusters can also be used as reading glasses, allowing older people to carry on reading and performing near vision tasks. In fact, because the lenses in Eyejusters can be varied they can do much more than ordinary reading glasses – allowing adjustment for different distances and different members of a family.

Eyejusters do not prevent or reverse macular degeneration, cataract, glaucoma or any ophthalmic condition other than refractive error (short- and long-sightedness).

What conditions do Eyejusters work for?
Please take a look at our distribution kits, which come with all the materials, training and charts you need to get started.
How can I start distributing these glasses?
Our lenses are made in the United Kingdom under strict process conditions to ensure the best optical quality. Other parts are currently made in either the UK or China and assembled in the UK.
Where are they made?
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