Epileptic Flashing Lights

It seems that whenever something or someone goes haywire, fails or is about to explode, light is going to flash rapidly, randomly and brightly, whether it originates from buttons, lamps, screens or even eyes and orifices. Justified in failing lightbulbs and warning lamps, but may otherwise lead to moments of What Do You Mean It's Not Awesome?. Often used in the Stalker Sequence to create suspense and allow the villain or the monster to sneak up on the protagonist with impunity.

Notable offenders are the (more contemporary) horror and science fiction genres. Somehow many film and video game-makers believe Everything Is Better with Flashing even though it's not always that awesome.

Not in any way related to Epileptic Trees. Compare to Power Glows, where light produces a positive effect, and Glowing Eyes of Doom, which implies imminent evil rather than imminent (self)destruction. See also Deadly Fireworks Display, Stop-Motion Lighting and Throat Light. May fall under Sensory Abuse.

Anime & Manga

 * Pokémon will forever be haunted by the Electric Soldier Porygon incident. Episode 38 aired only once on December 12 1997 in Japan, and in the half-hour that it showed, 700 kids had seizures and had to be hospitalized. The episode was never aired anywhere else in the world, having been outright banned by Japanese law, and holds the infamous world record of most seizures induced by a television show. As a result of this reputation, Porygon (and later, its evolutions, Porygon2 and Porygon-Z) have never appeared in any episode or movie since... which serves as little more than insult to injury, since it wasn't Porygon who set off the Epileptic Flashing Lights, but Pikachu hitting the vaccine missiles that produced the seizure-inducing red and blue flashes. Pikachu then proceeded to appear in every episode and movie since...
 * The actual stinger is that soon after the airing of the episode in question (which alone wasn't responsible for the total seizure count), several news outlets in Japan AIRED THE OFFENDING SCENE AGAIN as part of stories covering the incident, causing more seizures...
 * "You did it, Pikachu!"
 * Neon Genesis Evangelion combines this with Unreadably Fast Text on a few occasions, especially in episode 22.
 * Dragonball Z has a serious case of this when Gohan and Super Perfect Cell are using their Kamehamehas against each other in a final battle.

Films -- Live-Action

 * Alien: The Trope Maker.
 * Matrix Revolutions: Though a borderline case, the trope is played relatively straight when Big Bad Smith absorbs Neo in the Matrix and the Deux Ex Machina (no, not THAT Deus Ex Machina) unplugs Neo in the real world. This disconnects Smith from the Matrix, causing each and every of his multiple selves to suffer epileptic glowing from the eyes over the next few minutes and explode.
 * Dark Star has several animated FX with alternating light and dark frames, prompting TV stations to sometimes flash up warnings at the start.
 * Averted in the film of The Andromeda Strain. Ruth Leavitt is epileptic and suffers a petit mal seizure when looking at a flashing light. However, the light isn't flashing nearly fast enough to cause a seizure in real life. (See also Literature below.)
 * There's an art house movie which consists entirely of alternate black and white frames - an epileptic's nightmare.
 * The vampire birth scene in The Twilight Saga: Breaking Dawn Part 1 employed this and caused numerous viewers to have seizures.

Literature

 * In The Andromeda Strain, the flashing alarm lights of the secret underground Wildfire laboratory literally become epileptic flashing lights when Dr. Peter Leavitt suffers an epileptic fit because of them.
 * In the film, the male Dr. Peter Leavitt in the novel is changed into a woman, Dr. Ruth Leavitt. Rather than the epileptic fit being just another problem to deal with, it becomes a Plot Point when a flashing computer screen causes her to have an absence (trancelike) seizure and not notice the vital information it's transmitting.

Live-Action TV

 * The Weeping Angels in Doctor Who seem to have the ability to cause this as a power. Since they can only move when unseen...
 * Kamen Rider Black's finishers later in the series. You will go blind.
 * The BBC's news bulletins always issue warnings before showing footage containing flash photography.

Music

 * This may be the goal of every lighting technician at rock/metal concerts.
 * Too many videos to count.
 * Kanye West did two in a row lately, leading some to joke he has something against epileptics.
 * Slayer and their concerts. 30 straight minutes of strobes and people probably seizing, almost seizing, or leaving before seizing.
 * Meshuggah. POLYRYTHMIC epileptic strobes. Freaking insane. And amazing

Theater

 * Disney's Aladdin: The Stage Musical uses this during the Cave of Wonders sequence and at a few other points. Warning sign included.

Video Games

 * F.E.A.R and it's expansion packs and sequels.
 * Star Fox 64 has several bosses that get light-emitting cracks before exploding.
 * In the NES game Iron Tank, bosses display a seizure-inducing light show when exploding. This effect is also used when V2 rockets explode, one notable example about 2/3 through the first level, and even more pronounced when the player is killed. Photosensitive people should stay clear.
 * The arcade version of Salamander features an enemy that does this.
 * The disco/strip club in Duke Nukem 3D.
 * All text (and graphics) in Burn the Trash.
 * Beat Hazard is basically epilepsy, now availiable in videogame format.
 * La-Mulana does this after Bahamut is defeated.
 * Spheres of Chaos is based on bright colors and flashes. One of the options include screen flashing when one particular enemy is defeated. The game warns about seizure possibilities.
 * Techno. Kitten. Adventures. Enough said. If not enough said, http://www.youtube.com/watch?v=2d2B0wQwqZU
 * In Zelda II the Adventure of Link, the screen flashes as bosses die. When Link dies, the screen flashes multiple colours save for Link's black silhouette. These effects have been considerably toned down in rereleases, however.
 * Boss deaths in Transformers: Convoy no Nazo.
 * Child of Eden uses these a lot.
 * Brutal Mario, a hack of Super Mario World, has the first Koopaling boss in a room full of multicolored flashing lights as you hit him.
 * The Japanese Pokémon Red, Green, and Blue uses screen flashes as part of the animation for the attack localized as Thunderbolt internationally. This was removed in the international releases and Yellow because of the Porygon incident and the introduction of the Game Boy Color.

Web Comics

 * Homestuck used rapidly flashing lights in the Flash "[S Jade: Wake up]", to the point of it falling under this trope. Andrew Hussie made sure to construct it so as to avoid triggering seizures though, despite the rapid flashing. As a whole, the series uses rapidly alternating and often brightly colored animation fairly often, though the only known time cases of photosensitives having problems with it have arisen is the second intermission's Flash, which caused multiple reports of headaches; it's safe to view it on YouTube, though, as the site's compression pretty much destroys the framerate to the point where it's not a problem.

Western Animation

 * In Code Lyoko, whenever one of XANA's monster is struck by the heroes' weapons, bright light pour from the wound -- just before it explodes if the Eye of XANA logo is hit.
 * On the season 10 The Simpsons episode "30 Minutes Over Tokyo," Bart watches a robot anime, recognizing it as "that cartoon that causes seizures." Sure enough, the show has flashing lights that gives Bart, Lisa, and Marge seizures (Homer initially fakes it because he sees everyone else on the floor doing it). When it cuts to commercial, everyone snaps out of it. When it comes back from commercial, everyone starts seizing again. To drive the point further home, the cartoon is called, "Battling Seizure Robots."
 * South Park also parodied the Pokémon incident with "Chinpokomon" - though in this case Kenny got the seizure from the video game instead of the cartoon. (And he died of it, of course)
 * The Problem Solverz is rather infamous for its bright and flashy animation style.

Real Life

 * Lightbulbs have a tendency to act like this if they don't outright pop, which perhaps makes this the Ur Example.
 * Flickering light from fires, such as candlelight, can produce a similar effect. Not as effective though, since the luminosity contrast between on/off for fires that flicker (like a candle flame that's about to die) tends to be smaller than the contrast between on/off for lightbulbs.
 * Fluorescent lights can be this for people with sensitive enough vision.
 * Seizures can also be set off by the damn flashing lights they have on construction vehicles for night work, some types of bicycle lights, and even police car flashers.