Which Pokémon anime episode led to reports of 685 viewers being hospitalized in Japan?

“Dennō Senshi Porygon” led to reports of 685 viewers being hospitalized in Japan.

The episode aired on December 16, 1997, and included rapidly flashing red and blue light effects during an explosion sequence. Viewers reported symptoms such as dizziness, headaches, blurred vision, and seizures. Japanese emergency services transported hundreds of affected viewers to hospitals, creating an international media story.

The incident became known as the Pokémon shock and prompted broadcasters and animators to review photosensitive epilepsy risks. The episode was removed from circulation and has not been rebroadcast as part of the regular Pokémon anime lineup. Porygon and its evolutions also largely disappeared from subsequent television episodes.

The number 685 refers to viewers reported as hospitalized after the broadcast, not to the total number of people who experienced symptoms. Reports also described additional viewers who felt unwell but did not require hospitalization. The event influenced later Japanese television safety guidelines.