Did you know that epilepsy isn’t just one disease; rather, it is a group of neurological diseases all characterized by epileptic seizures? This month we’re talking about this disorder that impacts roughly 0.6% percent of the Canadian population, including epilepsy triggers, what to do after diagnosis, and how it impacts eye health.
The cause of seizures can be genetic or may be brought on after a stroke, head trauma, or other injuries to the nervous system. Once a person is prone to seizures, there are a variety of triggers that can possibly lead to epileptic attacks, ranging from lack of sleep, to stress, to visual stimuli.
Those affected by visual stimuli are said to have photosensitive epilepsy.
Photosensitive epilepsy affects about 3 percent of epileptics. Flashing lights or rapidly changing images can bring on a seizure, though the particular speed of the flash/image change affects everyone differently. For example, flashing lights at a rate of 16 to 25 times per second are more likely to be epilepsy triggers. However, some individuals can react anywhere from 3 times per second to 60 times per second.
To date, television has been the one of the main causes of photosensitive epileptic seizures. Though TV broadcast guidelines exist to safeguard viewers from harm, certain show scenes have inadvertently been broadcast, sending some susceptible viewers into seizure. Most notably in Japan, one particular episode of Pokémon featured a red and blue strobe-like explosion, which then induced 685 epileptic seizures in young viewers.
People who know they may be prone to photosensitive epileptic seizures can take a number of precautions. Epileptics are advised to watch television (or their computer monitors) in well-lit rooms and watch from a greater distance. Most light-induced seizures happen when the lit screen occupies a greater area of the viewer’s field of vision. People who know they are particularly at risk to light-induced seizures commonly seek medication to reduce sensitivity. According to research, polarized glasses for photosensitive epilepsy may also help by reducing glare.
In some cases, vision changes can potentially precede a seizure. A loss of peripheral vision or seeing double, for example, may be an indication to epileptics that a seizure may be about to occur. These effects are often short term and those who experience epilepsy should discuss any similar experiences with their doctor for proper assessment.
In Canada, an average of 14,000 people are diagnosed with epilepsy every year. More than half of those people are diagnosed before they are 10 years old, and in about half of those cases, seizures can be completely brought back under control. If you or someone you know has an epilepsy diagnosis, it’s important to check in with a doctor regularly to keep up with the latest treatments.
In addition to being National Epilepsy Awareness Month, November is also National Diabetes Awareness Month—learn more about this disease and its potential impact on vision health here.