Written by MJN
Exposure to certain visual stimuli such as flashing lights at certain intensities or visual patterns may trigger seizures. This condition is known as photosensitive epilepsy. It is estimated that it affects between 3% and 5% of people with epilepsy. Seizures occur as a result of an unusual reaction of the brain to the visual information it receives.
This type of epilepsy is most prevalent among children and teenagers, especially those with generalized epilepsy or juvenile myoclonic epilepsy. With aging it becomes less frequent and people become less sensitive to visual stimuli.
Among the main elements that can cause this type of seizure are television, video games, computer monitors, fluorescent lights, discotheque lights and geometric patterns. However, there are many other factors that must be combined to trigger the photosensitive reaction, such as:
- Flash frequency (i.e., how fast the light flashes)
- Brightness
- Contrast with backlighting
- Distance between viewer and light source
- Wavelength of light
- Whether the person’s eyes are open or closed
How do I know if I’m photosensitive?
Many people know that they are photosensitive if they have a seizure when exposed to flashing lights or patterns. An EEG may include photosensitive epilepsy tests.
How can I reduce risks?
- Take regular breaks off the screen.
- Sit away from the screen.
- Use the remote control to change channels.
- Watch TV or use a screen in a well-lit room.
- Change your browser settings to control moving images when surfing the Internet.
