Contents
- Introduction
- About photosensitive epilepsy
- About hertz (Hz)
- Diagnosing photosensitive epilepsy
- Ways to reduce the risk of seizures if you have photosensitive epilepsy
- Some possible seizure triggers for people with photosensitive epilepsy
- Computer and television screens
- Useful information and contacts
Introduction
The aim of this information is to tell you what photosensitive epilepsy is, who it affects and what might trigger a seizure if you have photosensitive epilepsy. There are also suggestions for reducing the risk of having a seizure.
About photosensitive epilepsy
Photosensitive epilepsy is a type of epilepsy, in which all, or almost all, seizures are triggered by flashing or flickering light. Both natural and artificial light may trigger seizures. Some patterns, like stripes or checks, can also trigger seizures for some people with photosensitive epilepsy.
Various types of seizure can be triggered by flashing or flickering light. These include tonic-clonic, absence, myoclonic and focal seizures. The most common is a tonic-clonic seizure. The seizure(s) will usually happen at the time of, or shortly after, looking at the trigger.
Around three in every 100 people with epilepsy have photosensitive epilepsy. It usually begins before the age of 20, most commonly between the ages of seven and 19. Photosensitive epilepsy affects more girls than boys.
Epilepsy Action has more information about epileptic seizures.
About hertz (Hz)
The word hertz (Hz) refers to how often something happens in a second. For example, it can mean the number of times something flashes or flickers in one second. It can also mean the number of times the scanning lines on televisions and computer monitors ‘refresh’ themselves in one second.
Most people with photosensitive epilepsy are sensitive to 16-25 Hz. Some people may be sensitive to rates as low as 3 Hz and as high as 60 Hz.
Diagnosing photosensitive epilepsy
If you have an epileptic seizure when looking at flashing or flickering lights or certain patterns, this is a sign that you may have photosensitive epilepsy.
Your doctor may ask you to have an electroencephalogram (EEG) test. This test records the electrical signals from your brain on an EEG machine. During the test, you will be asked to look at some flashing lights. If doing this changes the electrical signals in your brain, it may indicate that you have photosensitive epilepsy.
The person doing the test will usually try to stop the test before you actually have a seizure. However, there is a small risk that you will have a seizure when the test is done.
Epilepsy Action has more information about EEG tests and diagnosing epilepsy.
Ways to reduce the risk of seizures if you have photosensitive epilepsy
- Avoid looking at anything that you know may trigger a seizure.
- Avoid things that can increase your risk of having a seizure. These can include feeling tired or stressed, not having enough sleep and drinking alcohol.
- If you take epilepsy medicine, always take it as prescribed by your doctor.
- If you look at something that might trigger a seizure, don’t close your eyes. This could increase your risk of having a seizure. Instead, immediately cover one eye with the palm of your hand and turn away from the trigger. This reduces the number of brain cells that are stimulated and reduces the risk of a seizure happening.
Pay it forward
This resource is freely available as part of Epilepsy Action’s commitment to improving life for all those affected by epilepsy.
On average it costs £414 to produce an advice and information page – if you have valued using this resource, please text FUTURE to 70500 to donate £3 towards the cost of our future work. Terms and conditions. Thank you
We can provide references and information on the source material we use to write our epilepsy advice and information pages. Please contact our Epilepsy Helpline by email at helpline@epilepsy.org.uk.
Epilepsy Action would like to thank Professor G F A Harding, Emeritus Professor of Clinical Neurophysiology, Aston University and also Professor Stefano Seri, Professor of Clinical Neurophysiology at Aston University and Consultant at the Birmingham Children’s Hospital NHS Foundation Trust for their contribution to this information.
This information has been produced under the terms of The Information Standard.
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Updated March 2012To be reviewed March 2015
Comments: read the 31 comments or add yours
Comments
Th strobe light on the iPhone gave my 14 year old Doberman a violent seizure.
Hi Chantel.
Thank you for this information. It must have been a distressing experience for you and your dog. We will look at the impact of phone apps when reviewing our information on photosensitive epilepsy.
Kind regards
Vicky
Advice & Information Team
Hi,
I am at the age of 17 and I have been having what it seems like as epilepsy, but every time I have an EEG done it comes out normal. Symptoms include, jerking of the muscles, loss of consciousness, falling down, blurred vision, lightheadedness, confusion, head pounding, and dizziness. I only get these when I am watching TV, playing video games, watching people play at the park, and watching computer screens. Are these signs of having photosensitive epilepsy? Is it common for the EEG to come out normal?
Michael,
We have responded to you by email.
Regards
Diane Wallace
Advice and Information Team
Hi, I work for a company who do bathroom adaptations. I have a client who suffers from seizure's (I am not sure if he is a photosensitive epileptic sufferer, as the report said at the top that it is only 3 in a 100 that are) When he goes into the bathroom he walks in backwards because he doesn't like the light flickering on. Do you know if there are any bathroom light units that are up to current regs? (IP44 standard unit)
regards Jo
Hi Jo
People who have photosensitive epilepsy might have a seizure triggered by a fluorescent strip light or light bulb if it flickers because it is faulty. Otherwise, they should not cause a problem.
If your client does not have photosensitive epilepsy, there is no reason why any kind of lighting would cause him to have a seizure. Some people find different types off lighting uncomfortable, but this is not necessarily for any reason related to epilepsy.
We don’t have any information about any bathroom light units.
I hope that helps.
Amanda
Advice and Information Team
Thank you for your prompt reply. Yes that does help, I am going to discuss this with his occupational therapist.
Hi Jo,
You could try to replace them with LED light bulbs, they don't flicker and have a very balanced light intensity output. Failing that there are lighting specialists that can check levels and advise appropriately
My daughter is worried about having her photo taken for her free travel pass as she often experiences her pre tonic clonic aura in flashing & bright light, although she is on a very high dosage of two different medicines which have kept her seizure free for just over 12 months. Is it safe for her to have her photo taken? She is just beginning to get her confidence back so we could do without any setbacks. She had her first seizure whilst travelling alone on a bus so it is encouraging that she should even be contemplating obtaining a travel pass.
Hi Kathryn
I’m sorry to have to tell you this, but if your daughter has been seizure-free for 12 months, then she won’t be entitled to a free bus pass. This is because she would be able to apply for a driving licence now.
Just to answer your question anyway, if your daughter has been diagnosed with photosensitive epilepsy then she would have a problem with lights that flash at a certain frequency. So a single flash should be absolutely fine.
Cherry
Advice and Information Team
Bus pass information: https://www.epilepsy.org.uk/info/benefits/england#free-bus-fares
Photosensitive epilepsy: https://www.epilepsy.org.uk/info/photosensitive-epilepsy
Did I forget to mention that my daughter is also visually impaired as a result of the brain haemorrhage which also caused her epilepsy? She will never be allowed to drive!! Back to my question....
Hi Kathryn
If your daughter has been diagnosed with photosensitive epilepsy then she would have a problem with lights that flash at a certain frequency. So a single flash should be fine.
And whilst we can never be certain, I can reassure you that we have never had any reports of someone having a seizure triggered by having their photograph taken.
Thank you.
Cherry
Advice and Information Team
I have seen at least one person who had a pre-seizure reaction to a single photography flash. I don't know for sure that the person had experienced having a seizure under those circumstances but it definitely was a seizure hazard.
The Association for Autistic Community (US; our counterpart to the Autscape organisation in the UK) has a Seizure Policy which strictly prohibits flash photography in any public areas at their conferences.
I had an EEG done today. Every time they flashed the lights I got a cold feeling and would shake uncontrollable. Does this mean I have epilepsy?
Hi Tina
Sometimes, EEG tests can trigger seizures in people with epilepsy. However, there could be other reasons why you had these reactions, and it doesn’t necessarily mean that you have epilepsy. This is something you need to discuss with your doctor.
Best wishes
Amanda
Advice and Information Team
It looks like I will be dj at a friends wedding(usually do not dj) where some of the brides family has epilepsy and mentioned that they can not have strobe lights. Personally I think it would be a nice touch to have some of the lights that change colors but I am curious what kinds of the dj/party type lights are ok for photosensitive epilepsy.
Hi Christina
Thanks for your message. It’s great you’re taking the family’s thoughts into consideration. I hope our general information helps.
Photosensitive epilepsy is a relatively uncommon diagnosis. About 3 in 100 people with epilepsy have photosensitive epilepsy. Seizure triggers in photosensitive epilepsy vary. The flash rate of strobe lights in the UK is restricted to a maximum of four flashes a second by the Health and Safety Executive. This rate is considered to be safe for most people. However, some people with photosensitive epilepsy may still find strobe lights could trigger a seizure.
As you have been informed by the family that strobe lights are a concern, then it could be a reasonable adjustment that you not include them. This does not rule out other lighting effects, such as some lights that change colours, as long as they stay within the maximum of four flashes per seconds. It might be a good idea to discuss with those concerned what would be acceptable and work as best you are able to their requests.
You might find some of the Health and Safety Executive’s guidance special effects useful. And, if you have a video of the lighting you want to use in action, the Online Flash Test could help you figure out what would be best.
If we can be of any more help, please feel free to contact us again, either by email or the Epilepsy Helpline freephone 0808 800 5050.
Yours sincerely
Sacha Wellborn
Advice & Information Team
Our 7 year old daughter has been diagnosed with photosensitive epilepsy in the last week. She has been blue lighted to hospital 4 times in the last 3 weeks and has now been admitted to hospital until they can medicate it. A key concern has been gasping for breath when fitting, but that seems to have stopped last few days. Unfortunately, since starting meds a week ago, things seem to have got worse though. The after effects on her mental state are extremely concerning. She's come out of seizures twice not knowing who we as her parents are, regressing to the mental age of 3/4, angry, refusing to be comforted, running away, scared... Its so distressing. Consultants have changed meds, but all commenting they haven't seen anything quite like this before. Last night, she fitted 30/40 times, was terrified and confused. As parents its just awful not being able to really do anything. They are now exploring transferring her to an epilepsy specialist centre in London. She has had no other issues - she's bright, mature for her age and physically fit. MRI has ruled out anything else.
Dear Mat
That sounds like a really difficult situation for you all. We aren’t medically trained so are not in a position to suggest any more explanation than the doctors can. I think getting your daughter to an epilepsy specialist centre sounds like a really good idea. I do hope that happens soon., and you are able to get some explanation about what’s happening for your daughter.
Cherry
Advice and Information Team
HI 29 All tests came back normal flashing light eeg didn't effect me in there. But when I cane out of the hospital. I was walking funny being to keep a straight path instead my body was making me walk like I was drunk. Making move to the right and left like I was drunk or rocking boat. I went to get rechecked again cause in 2006 I collapsed and was jerking remembered a white ball before I ccollapsed. Another time I was in a pub about few years back I fell down the stairs but couldnt remember after three days. But when it hhappened was wondering how I got there was facing forward with my head against the wall. Can you still have photo sensitive iif tests came back normal. When someone comes up behind me and says boo or shouts in mmiddle of doing somethng the computer or my phone. I jumped up froze to the spot burst out crying with fright I have never liked loud noises I don't like getting to overheated same thing happened. Hd lcd telly blanked out while watching it. Concerts or cinemas I come out looking physio sid. Could it be photosensitivity.
I get a rising up feeling into my throat. Once Im roxannes my head dropped when someone was taking a pictute with me. When the loud bang from the disco forgot turn it down my whole body came down into a crouching mode back up again. Vision face burns up panicky voices sound louder than there actually are. Body feels painful. Feeling can describe comes over one te I took a degu outside not knowing what the he'll was doing. Or gone into a room.
Hi Katrina
What you are experiencing sounds very scary and distressing. If you haven’t already, it would be advisable to talk to your GP again.
The symptoms you have described are not typical symptoms of epilepsy. But epilepsy is a very individual condition. As there are a number of medical conditions that can cause symptoms similar to epilepsy, the doctor will need a history of your symptoms to help with their decision. You may wish to keep a diary of these events, to help the doctor.
If there is a connection to epilepsy it could be some type of focal seizure. In these seizures the epileptic activity starts in just a part of your brain. You may remain alert during this type of seizure, or you may not be aware of what is happening around you. You may have movements that you can’t control, or unusual sensations or feelings. Focal seizures can be very brief or last for minutes.
If you are still concerned you may have Photosensitive epilepsy talk to your doctor again. If your doctor thinks it’s necessary, they could arrange for you to have another EEG. In most cases, photosensitive epilepsy is picked up on an EEG.
It may also be helpful for you and your doctor if you keep a diary of your symptoms.
I hope this is of help. And I hope you get an explanation and help for these episodes soon.
Regards
Diane Wallace
Advice and Information Team
Hi I haven't had a fit in 9 yrs and I've bought tickets to watch one direction in concert in cardiff my daughters the biggest fan really want to go with her but worried about the strobe lighting any suggestions I have photosensitive epilepsy
Dear Beverly
Thanks for your message. Nine years seizure-free is quite an achievement.
If flashing lights are your seizure trigger, then a pop concert could be a risky setting for you. Our general suggestions to reduce the risk of seizure if you have photosensitive epilepsy are:
I hope the concert is a success for you and your daughter. If we can be of any more help, please feel free to contact us again, either by email or the Epilepsy Helpline freephone 0808 800 5050.
Yours sincerely
Sacha, Epilepsy Action Advice and Information Services Officer
Thankyou Sacha for your advice very helpful I was thinking of being glasses that keep all the glare and reflection out and that cost 100 pound what do u think? Is there any surgery that available?
I have been getting very bad headaches and sharp pains in my head. also confusion,memory loss and visual distortion. I havent had a fit for over 20 ears but wonder if it could come back. I was diagnosed wi4th epilepsy at18
Hi Louisa
Thank you for your question.
These sound like quiet distressing symptoms. It can be possible for epilepsy to return after many years. If it is epilepsy, it could be some type of focal seizure.
But the symptoms you explain could happen for various medical reasons. It would be advisable to seek a medical diagnosis.
https://www.epilepsy.org.uk/info/seizures/focal-seizures
Regards
Diane, Epilepsy Action Advice and Information Team
I am 39. Four months ago, I experienced my first ever noticeable seizure in a parking lot inside my car. I was frightened, sore, soiled, confused.... did not remember how to get home. I had no idea that it was a seizure. I couldn't think. After tests, heavy meds (more seizures), etc. we are aware that computer screens and flashing lights cause them quickly. However, I also have other triggers. My diagnosis now is focal epilepsy but compound partial with oçcasional crossovers. I will be admitted for a video eeg next week.
My question.... if I go to eye dr for an articulate glasses script, will that help? I am desperate to get back to life.
Thanks in advance.
Hello April
Seizures, particularly your first, can be terribly frightening. I’m sorry you’ve had to experience that. I hope you are starting to feel better.
We are not aware of any kinds of glasses that can help a person with photosensitive epilepsy. We are aware of tests and research being tried but as yet, nothing has become available.
You might like to ask on our online forum, forum4e, if others with photosensitive epilepsy have tried different glasses, and what their experience was.
Kind regards
Sacha
Epilepsy Action Advice and Information Team
hi I'm a rugby player I have had one definite concussion and since I have had some very lights knocks which I personally think did not hurt or cause much pain but 15-20 minutes later I started to get some dizziness, slurred speech, forgetting names but fine and well 30-40 minutes later and can remember everything. does this sound like concussion or some kind of seizure?
Hi Ryan
Thanks for your comment. That does sound concerning. But, we can’t say if your symptoms could be related to a seizure, or something else. We are not medically trained. If you think you may have had a seizure, it’s best if you talk to your family doctor (GP) about it. If the GP thinks it might be epilepsy, they can refer you to an epilepsy specialist for further diagnosis.
Kind regards
Sacha
Epilepsy Action Advice & Information Team