If your local optician can tint eyeglasses, it’s now possible to get protection from visually triggered seizures without ordering therapeutic Zeiss lenses. Lenses tinted using the new Deep Blue Zee lens tint are nearly the same color and appear to be just as effective as Zeiss Z1 F133 lenses.
Brain Power Inc. of Miami, and its UK arm, Brain Power Ltd. of Warwickshire, England, have introduced a cobalt blue optical tint that, according to the company, is nearly identical to the color-filtering specifications of the Z1 F133 lenses used in Capovilla’s photosensitivity studies. Brain Power, which supplies optical tints and laboratory equipment to opticians, optometrists, ophthalmologists, and lens manufacturers, developed the Deep Blue Zee tint specifically for photosensitivity protection. BPI describes itself as the world’s largest manufacturer of optical tints, chemicals, and instruments.
My daughter has been wearing a locally tinted pair for the past week and is finding them quite effective. She actually prefers them to the Zeiss because they aren’t quite as dark and therefore don’t darken her entire view as much. Because they’re not as dark, she is still able to see when watching DVDs from farther away from the screen.
The therapeutic properties of the Z1 F133 lens are due to its color and the way it blocks out shades of red. The amount of light a lens lets in across the color spectrum is measured by a spectrometer and shown in a spectrum curve (see graphs below), and each lens color has a unique spectrum curve. Capovilla and colleagues tried many colors and lens types before settling on the cobalt blue shade that lets in very little light in the red part of the spectrum. The big dip in this graph, excerpted from Capovilla’s 2006 study, shows that very little light is transmitted through the lens in the range of red wavelengths, measured in nanometers.
This is the Z1 spectrum curve from the Capovilla studies:
For the tint to be absorbed properly by the lens, the lens needs to be made of a particular plastic lens material, a plastic called C-39. If you have existing lenses you’d like tinted, they need to be made of CR-39 and can’t already have a hard coating that would prevent the lens from absorbing tint. BPI recommends that the lens be kept in the dye solution for at least 30 minutes to achieve the proper color. According to BPI, after half an hour of immersion in the dye, the absorption process goes more slowly.
As we’ve discovered in the past week, although the locally tinted ones weren’t as dark as the Zeiss lenses, it doesn’t seem to matter. If the lenses turn out not as dark as you’d like, your optician can make them darker by returning them to the dye solution for a little while. The price for tinted lenses will vary depending on the brand/quality of lens that your optician uses. And the quality and effectiveness may vary as well, depending on the optician’s skill, judgment, and choice of lens manufacturer.
The optician who tinted Alice’s blue lenses is:
Paul Dimos, owner
Eye Look Optical
1760 Massachusetts Ave
Lexington, MA 02420
The same day we got the new clip-ons, I had the idea that Alice might be able to watch certain DVDs (no anime!) on a small screen without needing to take so many breaks. She is doing well watching DVDs on a portable 7-inch DVD player. She sits several feet away from it so that the screen doesn’t take up too much of her field of vision. If she sat very close, that would cancel out the advantage of a small image that by its size minimizes the impact of video on her brain.
We now have a spare pair of cobalt blue clip-ons, allowing us the opportunity to compare the two side by side. Can you tell which is which?
I promised to share information about my daughter’s experience with the blue Zeiss Z1 F133 lenses that I’ve written about previously. In the past we got prescription glasses made with these lenses. But her prescription has changed every year and that meant ordering them all over again. So this last time we got her a new pair, we went with clip-ons. Here’s what I can tell you:
They absolutely do prevent seizures while Alice watches TV! They also prevent the seizures that happen when she reads uninterrupted for very long periods. And they’re handy for unexpected events out in the community—emergency lights, flash photography, and flickering fluorescent bulbs.
- Alice can feel that her eyes are under less stress as soon as she puts the glasses on. I guess it’s similar to feeling less uncomfortable when putting on regular sunglasses in bright sunlight.
- No hard data, but we suspect that even with the lenses, there is still some effect on her brain that sneaks through. We can’t say for sure, but we have a hunch that she has more unprovoked seizures in the day or days after watching TV. So we currently limit TV to a couple of half-hour sessions per day.
- I can’t report on the lenses’ effectiveness for preventing seizures from video games because we aren’t going there. Alice cannot be around video games, period, because she very quickly becomes intensely addicted. If left unsupervised with a computer, she will find a game site. If left alone to play video games with blue glasses on, she invariably removes the glasses when no one is around. There is something about that pre-seizure trance that her brain finds irresistible, even though her mind knows she’ll regret bringing on a seizure.
- The world looks kind of eerie all in the dim blue light that gets through the lenses. You can’t really discern color very well except for yellow, blue, and green.
- As expected, clip-ons are hard to keep track of when they’re not attached. (This is especially true for people with the attention and memory issues that often are associated with seizures). I just ordered another pair!
- If you get prescription glasses made from the Zeiss lenses, you’ll be switching off with your non-tinted regular prescription glasses–one pair on top of your head or hanging around your neck or at large and at risk of getting lost.
About the lenses
Z1 is the name of a filtering lens, made by Zeiss in Germany, that blocks out 80 percent of light. (I’ve previously said they are cross-polarized, which is incorrect.) These are the lenses used in the Capovilla studies. F133 refers to the particular shade of blue that was found in clinical tests to be most effective for photosensitive patients. Zeiss does the tinting. It’s a lens that was already commercially available in Italy, where the study was done. Researchers have looked at some other lenses as well, and I hope to learn more about those and pass along what I find out. Given how effective the Zeiss lenses are, though, there hasn’t been a lot of other investigation.
Like everything else having to do with seizures, what works for one person may not help another. Before investing in these you might want to just try polarized sunglasses to see how helpful those are. For some people that may be good enough protection.
How to obtain/order F133 lenses ***
In the past we were able to order them via Canada, but last year our optician said the Canadian supplier he was using couldn’t provide these lenses anymore. Through this blog I became aware of Antonio Bernabei, an optician in Rome who sells these. Contact him via email at firstname.lastname@example.org. He responds quickly, and his email English is quite good. You can order these lenses from him in any of several ways:
If you don’t wear prescription glasses, order blank F133 lenses and pick out a pair of eyeglass frames from an optician who will fit them for you. The optician can cut and insert the non-prescription F133 lenses when they arrive.
Cost for blank F133 lenses (like the two round lenses above):
- Plain lenses, for clip-ons: 99 Euros (as of this writing, approx. $130) plus shipping and insurance.
- Fee to cut blank lenses to fit into (most) sunglasses frames that you send: 20 Euros (as of this writing, approx. $26).
If you wear prescription eyeglasses and want a pair of prescription glasses made with the Zeiss lenses:
Send him your prescription and provide the designer name, color, and model number of a pair of frames you’ve chosen from your optician, and purchase the frames and lenses together from Antonio. He’ll send the assembled glasses, and this way you don’t need to ship him the frames first.
Cost: Varies according to the prescription, whether you need bifocals, etc.
If you want to wear the Zeiss lenses as a clip-on for your prescription glasses:
Order blank F133 lenses that your local optician can insert into a clip-on frame that attaches magnetically or hooks on to to your prescription glasses. Note that because Z1 F133 lenses are 2mm thick, most clip-on sunglasses frames cannot accommodate them. Typical custom clip-ons that match your eyeglass frame are made with a thin plastic lens that can’t be replaced without breaking either the lens or the frame. Ask your optician about clip-ons that have a tiny screw that allows the Zeiss lens to be inserted. We ended up buying an EasyTwist frame for the prescription glasses, which comes with a matching magnetic clip-on like the dark green one shown above.
Cost: see costs for non-prescription, blank lenses aboveAntonio Bernabei Ottica Bernabei Via Del Corso, 4 Rome Italy Phone: +39 06.3610190 www.otticabernabei.it email@example.com
Please send in comments to share your experience! I’ve learned a lot from some of you (especially L.H.) who also have been tracking these down. Have you been able to order the lenses from an optician closer to where you live? How well do the lenses work?
There are 2 sources I’ve recently heard about in North America. I believe they both have contacts with Canadian Zeiss representatives. Both optometrists can order the lenses and mail them to you.
Richard L. Silver, O.D.
Professional VisionCare Associates
14607 Ventura Blvd.
Sherman Oaks, CA, USA 91403
Office: (818) 789-3311
Fax: (818) 789-1047
Dr. Silver charges $400 for a pair of lenses, either blank or corrective. Thanks to L.L. for locating him and sharing contact information
Norm Johnson, manager
Optometrists’ Clinic Inc.
12318 Jasper Ave.
Canada T5N 3K5
The clinic provides the lenses for $250 (March 2012 price). You can order them as uncut lenses or, with a prescription and frame (or frame information), make up a pair of prescription glasses. In December 2013 Larra H. reports that you can also order them in a fit-over, standalone frame that covers the field of view more thoroughly. Cost for the Zeiss lenses has apparently dropped, so the plain Zeiss lenses in a fit-over frame is now down to $165.
*** May 5, 2012–After posting this, I found out about another way to get blue lenses that work just fine. You can work with your local optician and a blue tint they can use. See https://videogameseizures.wordpress.com/2012/04/27/seizure-protection-in-a-bottle/
In 1999 Italian researchers led by Giuseppe Capovilla published a study documenting their development of a special blue lens that showed great promise for protecting people sensitive to flashing light. The lens was manufactured for the researchers by the optics giant Zeiss and was given the name Z1. The Z1, which is a lovely shade of cobalt blue, blocks a great deal of the total incoming light. In addition it filters out the longer red wavelengths that are most likely to provoke seizures in those with photosensitivity. Ordinary polarized sunglasses, which some patients find helpful, don’t do this.
When wearing the Z1 lens, 77 percent of the photosensitive people in the study no longer showed any abnormalities on their EEG when exposed to flashing light. An additional 19 percent of study participants showed reductions in their abnormal EEG response. But it was a small study that involved only 83 participants.
When Capovilla and colleagues published a larger, follow-up study of 610 photosensitive individuals in 2006, they replicated these remarkable results. In the larger study, EEG abnormalities during exposure to flashing light disappeared in 463 (75.9%) of the participants, and the EEG abnormalities were considerably reduced in an additional 109 (17.9%). A mere 6.2 percent of the study participants experienced no change. Pretty impressive numbers. The authors concluded: “The Z1 lens is highly effective…in a very large number of photosensitive epilepsy patients irrespective of their epilepsy or antiepileptic drug treatment. The lens might become a valid resource in the daily activity of any clinician who cares for patients with epilepsy.”
The Z1 lens has the potential to change lives, allowing those with photosensitivity to participate in everyday activities without constant fear of visual seizure triggers. These lenses are an attractive alternative to anti-epileptic drugs, which have many unpleasant and potentially serious side effects and which in many cases are not effective for photosensitivity.
But these therapeutic lenses aren’t available in the US.** For a time it was possible to obtain prescription glasses made with Z1 lenses. Here in the US some opticians connected with Canadian suppliers who ordered the glasses from Germany. Now, due to corporate restructuring and distribution changes at Zeiss, the Z1 is unavailable here. It’s not clear whether the lenses are still available in Europe, where the follow-up study said they were commercially available. Meanwhile, Zeiss is selling “portable eyewear” to deliver 3D viewing for Playstations, iPods, iPads, and other video-delivery devices. What’s wrong with this picture?
My attempts to contact Zeiss about the Z1 have not been successful. Anyone out there have information on this that you can share with us here?
**3/28/12 Note: Thanks to responses from readers I have found several sources and my daughter has her new lenses! I recently posted quite a bit more about these lenses, including information on my daughter’s experiences with them and on how to order. Please see https://videogameseizures.wordpress.com/2012/03/11/life-with-zeiss-z1-f133-protective-lenses/
**5/15/12 Note: Now there is also a cobalt blue tint for lenses, developed as an alternative to the Zeiss lenses, that we have found equally effective. See https://videogameseizures.wordpress.com/2012/04/27/seizure-protection-in-a-bottle/