Some non-moving patterns with high contrast may trigger seizures in some people with photosensitive epilepsy. Examples of high contrast patterns are black and white stripes, some patterned materials and wallpapers, and sunlight through slatted blinds.
Polarized, blue lens sunglasses may help with photosensitivity. Ask your optician to find the deepest blue tint possible. The Z1 lens , listed in a study below, is available only in Italy. Polarized, blue lens are useful in preventing photosensitive seizures in many epilepsy patients.
Although the flash rate of strobe lights is restricted to four flashes a second by the Health and Safety Executive, some people with photosensitive epilepsy may still find strobe lights could trigger a seizure.
You may therefore wish to avoid night clubs or discos with strobe lights and other places where you could come across strobe lights (for example some theme park attractions).
If strobe lighting, or other flashing or flickering lights come on without warning, you should immediately cover one eye with the palm of your hand and turn away from the light.
Although some people find fluorescent lighting uncomfortable, the flicker rate (100 Hz) means it should not be a problem for most people. The flicker of a faulty fluorescent light, however, could trigger a seizure in people with photosensitive epilepsy.
Low energy light bulbs
We are not aware of any evidence that low energy light bulbs can directly trigger epileptic seizures. A leading expert in the field of photosensitive epilepsy has told us that, generally, low energy bulbs should not be a greater risk to people with photosensitive epilepsy than other light bulbs. We are currently monitoring this issue.
Sunlight in itself is unlikely to trigger seizure. However, sunlight reflected off wet surfaces, seen through leaves of trees, or when walking quickly past railings where the sun is shining through, could trigger seizures in people with photosensitive epilepsy.
If you have problems with photosensitive epilepsy and sunlight, wearing polarised sunglasses out of doors on sunny days can help to minimise the risk of seizures occurring, although it will not remove it entirely. The lenses work by removing reflected horizontal light. Your optician or retailer should be able to tell you which of the sunglasses they stock have polarised lenses.
Light seen through a fast-rotating ceiling fan could trigger seizures in some people with photosensitive epilepsy. Therefore, one with a slow rotating motion is advisable.
Flashing bicycle lights
There have been cases where red flashing lights (red light emitting diodes) on the back of bicycles have triggered seizures in people with photosensitive epilepsy, when they have been close to the lights as they were setting them up. If you have photosensitive epilepsy you may wish to avoid being close to these types of lights.
Flashing Christmas tree lights
These lights should comply with health and safety regulations before going on sale. The lights should not, therefore, flicker at a rate which could trigger seizures in the vast majority of people with photosensitive epilepsy.
These should not trigger seizures, unless it is possible to see a flicker, similar to one you might see with faulty fluorescent tubes.
There is no evidence that wind turbines can trigger seizures. The flicker frequency of wind turbines should be limited to 3 Hz. Newer wind turbines are usually built to operate at a frequency of 1 Hz or less.
If you have concerns about a planned or existing wind farm, you may wish to contact the British Wind Energy Association (BWEA), who can provide contact details of specific wind farm operators.
managing photosensitive epileptic patients.
Key words Photosensitivity • Blue-tinted lenses • Epilepsy • Electroencephalography
G. Capovilla • F. Beccaria • A. Romeo • P. Veggiotti • R. Canger • F. Paladin
Effectiveness of a particular blue lens on photoparoxysmal response in photosensitive epileptic patients
Received: 11 February 1999 / Accepted: 6 June 1999
O R I G I N A L
G. Capovilla (_) • F. Beccaria
Department of Child Neuropsychiatry
C. Poma Hospital, Mantova, Italy
Epilepsy Center, Fatebenefratelli Hospital, Milano, Italy
Department of Child Neuropsychiatry
C. Mondino Foundation, Pavia, Italy
Epilepsy Center, S. Paolo Hospital, Milano, Italy
Ital J Neurol Sci (1999) 20:161-166 © Springer-Verlag 1999
The aim of our work was to test a particular type of lens for photosensitivity control in photosensitive epileptic patients. Previous papers considered color and shade of dark to test lens efficacy. We added a new variable, namely lens material, to these well-known variables. We performed electroencephalography (EEG) and simultaneous video recordings in 83 epileptic patients to evaluate the effectiveness of these experimental blue lenses on photoparoxysmal response (PPR). In addition, we compared the lenses with four other types of commercially available lenses. We found that the experimental lens type was very effective for photosensitivity inhibition in epileptic subjects. Indeed, PPR disappeared in 64 of 83 patients (77%) and diminished in 16 (19%). All the other commercial lenses were less effective.
We think that this particular lens type could be useful in managing photosensitive epileptic patients.