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For many migraine sufferers, simply looking at certain visual patterns, such as stripes or polka dots, can trigger a severe headache. It can be especially problematic when the patterns involve flashes of light... such as when driving in a wooded area when the sun and the tree canopy create a pattern of light/shadow, light/shadow... or when sunlight is coming in through partially closed blinds... or even when exposed to almost imperceptibly flickering lights (including fluorescent bulbs).
Fortunately, many people who have regular migraines experience far fewer when they wear customized precision tinted lenses (PTLs), either as glasses or as contact lenses. (They are sometimes also called "precision ophthalmic tints" or "precision spectral filters.") While these lenses have been around for 20 years or so, until now, experts had not been exactly sure how the PTLs were able to stop the headaches. A recent study has finally unlocked the reason.
The study was done by Jie Huang, PhD, associate professor of radiology at Michigan State University in East Lansing, and other researchers at the University of Michigan in Ann Arbor and the University of Essex in the UK. So I called Dr. Huang to find out more. The findings were published in the June 2011 issue of Cephalalgia.
In this small study, Dr. Huang analyzed 11 people who had had at least 12 migraines in the previous year (the migraine group) and 11 people who either never got headaches or got minor tension-headaches three or fewer times a year (the control group). During one key part of the study, participants were asked to look at a stressful high-contrast striped pattern, a common migraine trigger, while wearing either neutral gray lenses... colored lenses that looked and acted like sunglasses... or customized PTLs that were also colored. Each participant tried each type of lens while brain activity was scanned by a functional magnetic resonance imaging scanner (fMRI).
What the study found: The imaging scan showed that looking through the PTLs -- but not through the other types of lenses -- immediately and significantly reduced hyperactivity in the visual cortexes of the brains of the migraine participants in response to the stressful pattern. Among the control nonmigrainesufferer) group, the PTLs had no different affect on their brain scans than any other type of lenses. Dr. Huang concluded that the suppressed hyperactivity in the visual cortex is probably the reason that migraine sufferers who wear them tend to experience fewer headaches.
In other words, the PTLs make the brain less susceptible to visual stimuli, such as changes in light and color patterns.
I called Helen Irlen, MA, LMFT, executive director of the Irlen Institute International in Long Beach, California, who developed Irlen Spectral Filters (her version of PTLs that are similar to the ones used in the study). Irlen Spectral Filters are tinted lenses that come in a variety of colors and can be used in both glasses and contact lenses -- and you don't need a prescription from an ophthalmologist to buy them. They're one of only a few types of PTLs that are available in the US. (Another type is available from the University of Utah's John A. Moran Eye Center in Salt Lake City, Utah, at 801-581-2352, http://uuhsc.utah.edu/moraneyecenter).
Irlen's PTLs, she told me, are customized for each individual. She said that when used in glasses, they look like tinted sunglasses from the outside, but when you wear them and look through them, they don't color what you see. Costs vary according to region but are approximately $150 for an initial evaluation to see whether Irlen PTLs might help you and then, if appropriate, approximately $450 for an analysis by a certified Irlen specialist to determine the color that will work best for you. If you wear glasses, then you can use whatever frames you like and whatever lenses suit your vision (even progressive lenses) -- one of Irlen's labs will tint them for you for about $155. Contact lenses can be tinted as well, and they do not change the color of your eyes (only the pupil area is tinted). For more information, visit www.Irlen.com.
Since preventing and treating migraine can be so frustratingly difficult for so many people, PTLs may be worth a shot -- especially since they might enable you to reduce or even eliminate the need for medications.
Jie Huang, PhD, associate professor of radiology at Michigan State University, East Lansing.
Helen Irlen, MA, LMFT, a learning disability specialist in Long Beach, California.