Photosensitive epilepsy

Photosensitive epilepsy is where someone has seizures that are triggered by flashing or flickering lights, or patterns. Any type of seizure could be triggered but tonic-clonic seizures are the most common.

There are 2 groups of people who have photosensitive epilepsy:

  1. People who only have seizures triggered by flashing or flickering lights, or patterns. This is sometimes called pure photosensitivity
  2. People who have seizures triggered by flashing or flickering lights or patterns but also have seizures at other times

Flashing and flickering lights

Different people will be affected by lights at different flash or flicker rates. Lights that flash or flicker between 16 and 25 times a second are the most likely to trigger seizures. But some people are sensitive to rates as low as 3 or as high as 60 a second.

Patterns

Different people will be affected by different types of pattern. Those patterns with a high contrast or some that move are more likely to trigger seizures.

How common is photosensitive epilepsy?

Around 3 in every 100 people with epilepsy have photosensitive epilepsy. If someone else in your family has photosensitive epilepsy, you are more likely to have it too. And if someone in your family has juvenile myoclonic epilepsy, you are also at higher risk of having photosensitive epilepsy.

There are many types of epilepsy and photosensitive epilepsy is most common in the following:

Is photosensitive epilepsy more common at a particular age?

Most people who develop photosensitive epilepsy are aged between 7 and 19 years old. But a small number of people who develop epilepsy as adults, also have photosensitive seizures. And some people who had photosensitive epilepsy as children, will continue having photosensitive seizures when they become adults. Females are more likely to have photosensitive epilepsy than males.

Are there tests that can show if I have photosensitive epilepsy?

Your doctor might ask you to have an electroencephalogram (EEG) test to see if you have photosensitive epilepsy. The EEG records the electrical signals from your brain on an EEG machine. During the test, you will be asked to look at some flashing lights, to see whether your brainwave patterns change. If they do, it may mean you have photosensitive epilepsy.

What is the treatment for photosensitive epilepsy?

The most common way to treat photosensitive epilepsy is with epilepsy medicines. This is to lower the risk of having a seizure. To reduce the risk further, try to avoid looking at things that you know can trigger a seizure.

If you find yourself coming across something that might trigger a seizure without warning:

  • Don’t close your eyes (this could cause a flicker effect)
  • Do cover one eye with the palm of your hand straight away
  • Do turn away from the possible trigger

Doing these things reduces the number of brain cells that could be stimulated and in that way the risk of a seizure happening is reduced.

Find out more about possible seizure triggers for people with photosensitive epilepsy.

If you would like to see this information with references, visit the Advice and Information references section of our website or contact our Epilepsy Action freephone helpline on 0808 800 5050.

Code: 
F157.05

This information has been produced under the terms of Epilepsy Action's information quality standards.

  • Updated June 2018
    To be reviewed June 2021

Comments: read the 4 comments or add yours

Comments

We think my daughter had a myoclonic seizure at school Thursday, stiffness in upper body and twitching for approx 7 mins. When she stopped twitching staff asked her questions and asked her to write, the school nurse said if a seizure she would not be able to write after. Is thus correct?

Submitted by Sharon Boyd-Gibb

Hi Sharon,

Thanks for your question.

What you describe happening to your daughter doesn’t sound like the kinds of seizures we normally hear about. But that doesn’t mean it isn’t a seizure - it’s hard to say without talking with you in more detail.

You’re very welcome to call us to talk through what happened, possible treatment and support at school.  

Our Epilepsy Helpline freephone 0808 800 5050 is open Monday to Thursday  8.30 am until 8.00pm, Friday 8.30 am to 4.30 and Saturday 10 am to 4 pm.

 

Regards

Ashley

Epilepsy Action Helpline Team

Submitted by Ashley - Epilep...

I was diagnosed with epilepsy when I was over 60. I had an abnormal EEG but had never had a seizure. I was put on Kepra which did not suit me and made my memory really bad, after two years I came off of it and went onto Lamotragine. I have had three seizures on 9 years, but each one has been the same which I do not see listed on this site. I always feel tired and go to sleep, then I remember nothing until I wake up and feel and am really sick, tired, confused and cannot remember having the seizure. My daughter tells me I squeeze my hands open and shut. I had my last seizure three years ago when coming into land on an aircraft, I was so, so sick and embarresed. My dosage on Lamotragine is only 25mg per day. I never go stiff, or twitch I just seem to go unconscious, I would really like your opinion on which sort of epilepsy I have. Because my seizures are so rare people do not believe I have epilepsy, but I do have to declare it on insurance documents etc. Could this be something else maybe? Advice please. I will be 70 in September.

Submitted by Lesley Capes
Hi. Certainly that doesn't seem to fit the usual picture of epilepsy. But there are many types. It is not common for someone to be diagnosed and put on epilepsy medicine on the basis of an abnormal EEG. So I am guessing there was something particular that they saw that justified that decision.
Clearly there is something happening for you on a neurological level. If you are not confident you have been diagnosed correctly you could always talk with your neurologist or GP about getting a second opinion. As you have so few seizures this will not necessarily be possible, but there's no harm in asking. I'm afraid we are unable to offer any explanation as we're not medically trained.
I hope you're able to get a clearer picture of what is happening for you soon.
Regards
Cherry
Epilepsy Action Helpline Team
Submitted by Cherry - Epilep...

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