Photosensitive epilepsy and working with computers

Around three to five per cent of people with epilepsy may have a seizure triggered by flashing or flickering light. This is called photosensitive epilepsy. If someone has photosensitive epilepsy this is likely to have shown up on an EEG (electroencephalogram) test – one of the most common tests used when a diagnosis of epilepsy is being considered.

If an employee is unsure whether they have photosensitive epilepsy or not, their doctor may be able to check their medical records. If the records show that a person is at risk of having seizures triggered by flashing or lights, they should also show which flicker rates that person should avoid.

Working with computers

Computer monitors

Many people think that people with photosensitive epilepsy are not able to use computers, because they will trigger a seizure. Although some images being displayed on the screen could be a problem, using a computer in itself is extremely unlikely to trigger a seizure.

Cathode ray tube (CRT)

These are the traditional, large monitors. CRTs have scan frequencies of 70 Hz and above. As most people with photosensitive epilepsy are sensitive to 16-25 Hz, CRTs, provided they are not faulty, are unlikely to trigger seizures.

Liquid crystal display (LCD) – also known as thin film transistor (TFT)

These thin, flat, screens are flicker free. This means they are unlikely to trigger seizures.

Risk from material displayed on computer monitors

If the material contains flashing, flickering or repetitive patterns, it will carry the same risk, whether it is viewed on a CRT monitor or an LCD monitor. Images displayed on LCDs are sharper and brighter than on CRTs. Some people are sensitive to patterns with a high contrast. Where these appear on an LCD screen, the brightness and sharpness of the screen may increase the risk to people with photosensitive epilepsy.

Anti-glare screens

Anti-glare screens can be of help in reducing glare. However, they do not reduce the flicker rate and are therefore of no specific benefit to people with photosensitive epilepsy.

Interactive whiteboards

Interactive whiteboards do not flicker, so are not likely to trigger seizures. However, there could be a risk to people with photosensitive epilepsy if the images shown on the whiteboard contain high contrast patterns or flashing or flickering at the frequencies known to trigger seizures.

Last updated 2 May 2007