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.

Types of monitors

Cathode ray tube (CRT)

These are the traditional, large monitors. CRTs have scan frequencies ranging from 60 to 100Hz and above. Most people with photosensitive epilepsy are sensitive to 16-25Hz. CRTs, provided they are set at refresh rates greater than 70Hz and 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. Therefore, LCD screens may carry a higher risk than CRTs for people with photosensitive epilepsy who are sensitive to patterns with a high contrast.

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.

Information updated November 2008