Photosensitivity and other triggers

Photosensitivity and other triggers

Questions from healthcare professionals

Q: Is there any research into whether seizures can be triggered by vibratory equipment such as vibrating mattresses; ball-pools and other vibratory/sensory related equipment used with children?

A: We have never come across this as a triggering factor for people with epilepsy, and we are not aware of any research in this area. However, triggers for seizures can be idiosyncratic and it is usually worth considering the effect on any one individual.
July 2010

Q: Is there any guidance on flash photography at events for people with photosensitive epilepsy?

A: Flash photography is usually not a problem on domestic cameras. However the motorised cameras which reload instantly can reach a high enough flash rate to affect people who are photosensitive particularly when large numbers of press cameras are involved, hence the warning broadcast on TV. The TUC banned flash photography within their conferences for this reason.
February 2010

Q: The Diabetic Retinopathy Screening Service for Wales is a mobile screening service for patients who have diabetes. Are there any guidelines on retinal screening with a digital camera (which uses a flash) for people with photosensitive epilepsy?

A: If retinal screening only uses a single flash, this is not likely to be an issue for people with photosensitive epilepsy. Photosensitivity relies on repeated flashes of light rather than single ones.
February 2010

Q: Is there any evidence of increased seizure activity in individuals who live in homes illuminated using low energy bulbs?

A: We are not aware of any evidence that using low energy light bulbs has an impact on seizures. Please see our statement on this.
December 2009

Q: Is there a condition called 'beat-sensitive epilepsy'? If so what is this?

A: Some people with epilepsy can find particular situations or events can set off, or trigger, their seizures. These triggers can vary: some are more common and some are very rare. Commonly-known triggers include tiredness and photosensitivity. However, for some people, reading, writing or doing maths can trigger seizures. Others may have startle-induced seizures (in response to sudden or unexpected stimuli such as noise or touch) or musicogenic seizures (in response to music). You can find out more about the latter trigger by using 'musicogenic' as the searchword in databases of research papers. People who only have seizures in response to a trigger are often defined as having a 'reflex epilepsy'. 
August 2008

Q: What is scotosensitivity?

A: Scotosensitivity is a sensitivity to darkness: where darkness triggers events to happen. This is like the opposite of photosensitivity (sensitivity to light). 
April 2008

Q: Can the flashing lights at zebra crossings trigger seizures for people with photosensitive epilepsy?

A: These flashing lights are unlikely to trigger seizures for people with epilepsy.
January 2008

Q: I know a young woman with epilepsy and learning disabilities. She has seizures every time she flies in a plane. Why would this be: is it due to lower oxygen levels at altitude?

A: It is not likely that lower oxygen levels in a plane would cause seizures. If this is a regular pattern for an individual, looking at treatment options, such as taking clobazam before the flight, might be beneficial.
January 2008

Q: I am an Orthoptist, and we do visual field testing. Are there any problems doing visual field tests on individuals with history of seizures, especially with respect to photosensitive epilepsy?

A: We are not aware of there being any particular risks for people with epilepsy. However, it is worth bearing in mind that epilepsy is an individual condition, and some people have seizure triggers that can be specific to them.
December 2007

Q: Can a person with nocturnal epilepsy only become at increased risk of awake seizures if he does night shifts?

A: A person whose seizures are triggered by sleep deprivation could be at risk if changes to sleep pattern occur. Usually if someone only has nocturnal seizures this pattern is preserved.
November 2007

Q: Most schools now have interactive whiteboards in the classrooms. Several of my patients have reported increased seizures or headache/feeling unwell whilst using them. Any advice?

A: We’re not aware of any definitive evidence regarding the use of interactive whiteboards by people with epilepsy, however it may be worth considering the following suggestions. Many of these are general suggestions, not specific to whiteboards.

Try to ensure that the image is well focused

Avoid rapid or excessive scrolling

Sitting further away from the screen may help

Images with a pale colour background may be better than those with a white background

If possible try to reduce glare

A matt screen may be better than a shiny screen

Whiteboards that use a projector to project the image onto a screen may cause more difficulties than those that use a flat (LCD) screen, as there may be some vibration

The nature of the image may be a factor – moving geometric shapes and patterns may cause difficulties.
July 2006

Q: Are there any UK or international guidelines to help ensure that products with strobing lights will not trigger photosensitive epilepsy? Are there agencies that help test such devices?

A: We're not aware of international guidelines. The only UK guidelines refer to flashing in TV images. This website may be of use: Harding flash and pattern analyser. There is also information about photosensitivity on this site.
June 2006

Q: Has the use of acetone and acrylic liquid been known to trigger seizures?

A: Acetone and acrylic liquid have not been known to trigger seizures.
October 2005

Q: Are there any particular colours that could trigger seizures?

A: Epilepsy is a very individual condition, and people have different and specific triggers for their seizures. However there are no particular colours known to trigger seizures.
September 2005

Q: We use interactive whiteboards in the classroom. Could they trigger a seizure in students who may be susceptible? We have advice on computers, are the guidelines the same?

A: The guidelines are similar to those for computers. Only those children with epilepsy who are photosensitive could be affected, and this is only a very small percentage of people with epilepsy. Where the whiteboards use a flat (LCD) screen, there is very little risk. If the whiteboard uses a projector to project the image onto a screen, then there could potentially be a problem if there was some vibration of the projector. This would also depend on the nature of the image being projected, as seizures can also be triggered in people with photosensitive epilepsy by moving geometric shapes and patterns.
May 2005

Q: Can epileptic seizures be induced in idiopathic and symptomatic focal epilepsy syndromes by flickering lights?

A: Yes they can.
March 2005

Q: In photosensitive epilepsy, what is the range of Hz that causes problems?

A: Only a few percent of people with epilepsy have seizures induced by flashing lights. The frequency of flashing light which is most likely to trigger seizures varies from person to person. Generally it is between 5 and 30 flashes per second (Hz). 
October 2004

Q: I have heard it is recommended that people who have epilepsy should avoid having too much milk and are recommended not to drink coke or even diet coke as it can affect their epilepsy. Is this true?

A: Epilepsy is a very individual condition and different people will find that they have different triggers for their seizures. There is no general recommendation that people with epilepsy should not drink or eat certain things. However people may sometimes feel that particular drinks seem to affect their seizures. Please see other questions on this page for more information.
April 2004

Q: It has been suggested that airlines are planning to reduce the amount of oxygen in aircraft cabins. Could this induce seizures in people with epilepsy?

A: This would probably not induce seizures, however it has not been tested as far as we are aware.
March 2004

Q: Can swallowing/eating food be trigger factors for seizures?

A: This is possible. It is also worth considering other possible associations with eating, for example situations in which the meal is anxiety-provoking, in which case anxiety/stress might be the trigger.
February 2004

Q: Can decorative glass or textured glass cause people to have a seizure?

A: In people with photosensitive epilepsy, seizures are triggered by flashing or flickering lights. They can also be triggered by geometric shapes and patterns, occurring in a variety of situations. Other factors may contribute, including the background illumination and the wavelength of the light.
January 2004

Please note: Epilepsy Society is unable to provide a medical opinion on specific cases. Responses contain information relating to the general principles of investigation and management. Answers are not, and should not be assumed to be, direct medical advice.