It is estimated that about 3 percent of the more than three million Americans with epilepsy suffer from seizures because of exposure to intense flashing lights or certain visual patterns. The condition is called photosensitive epilepsy, which is more common among children and adolescents, according to the Epilepsy Foundation. The disorder becomes less frequent as people age. There are few people in their mid twenties who are victims of these triggers. Along with strobe lights, people may experience seizures through flickering or rolling images of television screens, video games and computer monitors. There are people who do not have epilepsy but experience seizures because of sensitivity to flickering light or visual patterns. They may have other conditions that are vulnerable to ultraviolet light. They also may not develop full seizures, but instead experience headaches, nausea, dizziness and other attacks.
The seizures are most likely caused by the frequency or speed of the flashing light. The timing and intensity differs from person to person. Flashing lights are considered harmful to people who have seizures if there is a frequency of five to 30 flashes per second. Causes of the seizures may also include the brightness of the flashing lights, the contrast with background lighting, the distance between the person and the light source, the wavelength of the light and the person’s eyes being opened or closed to the source. It is believed that a combination of these factors will trigger the attacks. The effects on the brain are not fully understood, but it is believed that the condition involves the primary visual cortex, which processes visual information, explains Wired Science. Flashing patterns apparently overwhelm the cortex to set off a heavy number of neurons that spread to other parts of the brain. The malfunction causes photosensitive reactions in some people.
Your doctor can diagnose photosensitive epilepsy and may prescribe medication. You should avoid certain kinds of flashing lights. When suddenly in the presence of possibly offensive light sources, you can cover one eye and turn away. If you do know that you suffer from photosensitive seizures, you should sit more than 6 feet from a television to be cautious, according to Epilepsy Canada. The strobe effect can appear without warning because of flickering or rolling images. Computer monitors are rare and produce very little risk for inducing photosensitive seizures. Strobe lights and electronic devices often include warnings on packaging about possibly inducing seizures for people with photosensitive disorders.