Many of you have heard of this through whatever lines urban legends go through. On December 18, 1997 around 6:50 p.m. in Japan, about 618 children were taken to the hospital because they had suffered an epileptic seizure. The cause was one television program airing its 38th episode for the first time. The show is now well-known as Pokemon.

Millions of Japanese people gathered around their televisions to watch one of their favorite shows. Also, because of the way that rooms are set up in much of Japan, most people were sitting less than five feet away from their large televisions. At a certain climatic point of the episode, the animators used a popular anime technique called "paka paka," which involves alternating colored lights in order to create tension.

Akinori Hoshika, a neurologist, said that such optical stimulation can cause a varied amount of effects and particulary so on children because of their less developed brains and central nervous systems. Also the fact that the alternating colors used were red and blue, which are on opposite ends of the light spectrum, are also a major factor in the seizures produced.

Further investigations into the event produced that most of the children that actually did suffer seizures also suffered from a medical symptom known as "photosensitive epilepsy." About 0.5 to 0.8% of children from 4-14 have this symptom.

After this event(other than Nintendo's stock dropping five percent in the Tokyo stock market and causing a few more seizures and the such when a news broadcast covering the story showing the clip), Japanese television officials and medical officials created a set of rules to lessen the chance of this occurring again. The rules set were:

  • No flashing images with red should flicker faster than three times per second, and images without red should not flicker faster than five times per second.
  • Flashing images should last no longer than two seconds.
  • Stripes, whorls, and concentric circles should not take up an entire screen.
Also, the episode was edited to be "safe" for viewing, but was still promised to never be aired again.

This event became popularized once again in the The Simpsons episode "Thirty Minutes Over Tokyo" that was aired on May 16, 1999(a year plus after the event) with the fictional TV series "Battleing Seizure Robots."

What's the lesson to be learnt from this? Well, other than the fact that most animators aren't aware of the medical effect of their shows, and to be aware of flashing colors. Don't sit too close to your television, there's a less chance of being affected by something as odd as this.

Another reason not to sit too close to a CRT-based TV set is the electromagnetic radiation it emanates. A cathode-ray tube is basically an electron gun aimed at a phosphor-coated screen facing the viewer, and a large electromagnetic field extends for some distance beyond the front of the set. There are even products such as the EMF-Bioshield® one can buy to minimize this radiation.

This has also been parodied by the Simpsons (almost everything has been parodied by them at one time or another) in episode 2F07, Grampa vs. Sexual Inadequacy. In it, Homer finds himself in his childhood home, and the living room wall has a shadow of Homer as a child burned into it by the Radiation King TV set. The scene then shifts to his memory of watching it in the refulgent radiation of TV the set in the process of creating that distinctive shadow on the wall.
