When you play a game ranked in the GameSpot or New Yorker Top 10 video games of 2017, the chances are about even that you will be exposed to images that could trigger photosensitive seizures. These images, which violate established guidelines for reducing the risk of photosensitive seizures, appear in 6 of the games in a combined Top 10 list. In 7 games these images were not found (some games are on both Top 10 lists).
What are photosensitive seizures?
Photosensitive seizures can occur when people with photosensitive epilepsy are exposed to intense visual stimuli: bright, rapid flashing light and bold patterns with strong contrasts. An unknown segment of the population has photosensitive epilepsy, including people with no history of seizures. It is under-reported and under-diagnosed.
In those who develop the condition, photosensitive epilepsy typically is hidden until the first noticeable seizure occurs in the presence of bright flashing or patterns. Most people with other types of epilepsy are not photosensitive. In other types of epilepsy, seizures are much more unpredictable.
Seizures can be of any type, from tonic-clonic episodes with loss of consciousness to brief absence seizures that can be as subtle as a brief hesitation or stare. Most people do not have photosensitive epilepsy, but many who do are unaware that they have the condition until a they experience a seizure during or after exposure to flashing or patterned images. Some individuals may have seizures that are too subtle to notice.
The seizure reduction guidelines test
Guidelines for seizure reduction originated in 1994, when the UK adopted technical guidelines to accommodate TV viewers with photosensitive epilepsy. These guidelines, based on studies by photosensitive epilepsy experts, outline the characteristics of flash rates and spatial patterns that typically trigger seizures in people with photosensitive epilepsy. They were later updated and some have been adopted by the World Wide Web Consortium (WC3), the international group that produces website standards for all types of applications, and the International Telecommunication Union.
The guidelines define criteria for photosensitive seizure risk involving:
- flash rate greater than 3 per second and less than 60
- stripes and geometric patterns with high contrast
- large areas of very bright (“saturated”) red
- any of the above problem images taking up more than one quarter of the total screen area
Visuals adhering to these guidelines are unlikely to provoke seizures in 97% of people with photosensitive epilepsy.
Testing video games for compliance with guidelines
Although most games carry seizure warnings, not all games contain the types of images that can bring on seizures. The warnings are not specific to the content of a given game, so consumers who pay attention to the warning don’t know whether it pertains to the game they are about to use. So I test them.
I tested the games using downloaded clips of gameplay that I loaded into an application called the Harding Flash and Pattern Analyzer. The FPA is widely used by TV producers and networks in the UK—including by the BBC—to reduce the risk of seizures from material on broadcast TV, and is used by some game studios. It examines video sequences frame by frame for very specific and measurable image qualities that research shows can trigger seizures.
Local TV news ran a feature on seven-year-old Khloe of Aiken County, SC after she experienced a 30-minute seizure triggered by a fidget spinner. She’d never had a seizure before. The spinners, the latest craze in toys/gadgets, have already drawn criticism because children can be injured by them or choke on the small parts, and because they create distractions in classrooms. Khloe’s experience demonstrates another reason to be wary of fidget spinners: they create visual effects that can bring on seizures, even in people with no seizure history.
How does a spinner cause seizures?
Seizures induced by visual stimuli can be triggered in people with a condition known as photosensitive epilepsy. Typical triggers include rapidly flashing strobe lights, video games, and TV, as well as rotating helicopter blades and spoked wheels. Because rotating blades and spokes make rhythmic visual patterns where parts of the image rapidly alternate between light and dark, they can have a similar effect on the brain’s visual cortex as flashing lights. Because photosensitive epilepsy can emerge in people with no history of seizures, people may learn they have the condition only after experiencing a seizure.
Added risk from LED lights…
The risk of spinners triggering seizures is heightened by the flashing LED lights on some versions. Varleisha Gibbs, PhD, chair and director of the occupational therapy master’s program at Wesley College, expressed concern about this possibility in a May piece on Fatherly.com, “One of the triggers for seizure disorders is strobe lights…I would fear that could be a trigger.” Khloe’s seizure happened while she using a spinner with LED lights. She owns several others, without lights, that have not triggered seizures.
If kids turn out the lights to watch the spinner flashing in the dark, the strobing lights create even more of a seizure risk because of the contrast in brightness between the LEDs and the surrounding darkness.
Should I be concerned even if my child isn’t having seizures?
Your child could be having seizures you and the child aren’t aware of. Not all seizures involve convulsions, and many seizures aren’t noticed because their outward signs are subtle or simply not visible. Even if you can’t see them happening, seizures can leave your child with fatigue, confusion, mood problems, and other issues. We learned this after discovering that our daughter experienced unseen seizures while playing video games.
Vulnerable kids with ADHD and/or autism
The kids for whom these fidget spinners were initially intended to help (to increase focus, decrease anxiety) are probably more vulnerable than most other kids to visually induced seizures. Young people with ADHD and autism are more likely to have sensory processing issues that can include photosensitive epilepsy.
Note: Unfortunately, the WJBF TV news story about Khloe’s seizure, now posted on the station’s website and on YouTube, shows close-ups of the LED spinner in motion. Do not watch it if you are vulnerable to visually induced seizures! The clip includes images that exceed recommended limits on “safe” flash frequency. Watch anyway, at your own risk? Click here.
Riot Games, publisher of the hugely popular League of Legends game, responded quickly to a user reporting a seizure from the game. What happened this month is both a short and sweet case study in customer care, and a mystery.
Two days after a new animated log-in screen for League of Legends appeared, two users reported on a forum that the visual effects of that image caused a seizure. Several others said that the jerking of the image every few seconds produced uncomfortable and unusual sensations.
After the first user posted about his experience, Riot Games:
- took down and replaced the animated image
- announced the fix
- noted the company already uses software to test its games for seizure-triggering images and added, “…but if that isn’t enough we need to know.”
- thanked the user for pointing out the problem so it could be fixed
You can read the respectful exchange that unfolded in the League of Legends subreddit here.
In this instance, the fix was simple. Since the image sequence causing the problem occurs in an isolated part of the code, outside of game play itself. Riot Games simply replaced the login-in screen with a prior version. Riot posted this update: “We take this stuff super seriously and we’re grateful to [the original poster] for raising visibility on the issue so we could solve it.”
The mystery: What triggered the seizures?
On to the mystery. If Riot uses software to test its games for the possibility of triggering seizures, how did this image get through the testing process? Looking at the image (I do not have photosensitive epilepsy) it doesn’t show obvious violations of image safety guidelines. Because there’s an interval of some seconds between the periodic vibration of the image, those shifts don’t create a flashing effect. (One user described it as a “shudder.”) And there are no bold patterns that trigger seizures in some individuals.
I ran the image sequence through the seizure guidelines test software and, sure enough, the periodic shake barely registered. I consulted Prof. Arnold Wilkins of the University of Essex, a leading researcher in visual effects that influence the brain.
He examined the sequence frame by frame (video typically runs at about 30 frames/second) and found a single blurred frame in each “shudder” that differed from the rest. He suggests that the resulting disruption in an otherwise stable image is “profoundly disturbing” to the visual system. Prof. Wilkins advised that even wearing colored lenses, which are remarkably effective in reducing or eliminating seizures triggered by flicker, probably would help only slightly in this instance.
No guarantees of safety
While many of the guidelines for seizure-causing images have been carefully defined through research, we clearly don’t know everything yet. So even developers who follow image safety guidelines and test their products for a gaming experience without seizures can produce visual effects that are unsafe for those with photosensitive epilepsy.
Five of New York Magazine’s top ten video games of 2016 don’t meet guidelines for reducing the risk of visually provoked seizures. Developers of these popular games could have designed the visuals in a way that lowers the seizure risk to users, but didn’t.
Guidelines for reducing the risk of seizures triggered by video images were published in 1994, when the UK required that all TV programs and advertisements meet those visual safety standards. The same guidelines for making television images safer could easily be adhered to when developing video game visuals. No regulations on seizure-inducing images in video games have ever been enacted, so game developers have no incentive to work within the guidelines.
Instead, for many years game publishers have provided a seizure warning that makes it extremely difficult for consumers to take legal action in case of a seizure. Some games may in fact conform to seizure-reduction guidelines, but because the seizure warnings appear on all games, consumers can’t know which ones are riskier. The warnings began appearing in 1991 in response to the first video-game-seizure consumer lawsuits.
What compliance with the guidelines means
Many popular games don’t meet the guidelines, as demonstrated by my testing of New York Magazine‘s favorite games. A couple of the failing games were among the top five first-person shooter games selected by Forbes.
I tested video clips from gameplay and promotional trailers for the games on the list using software that identifies video sequences that don’t comply with the guidelines. The software is designed for game developers and video producers to test their moving images for compliance.
Note that for the games that didn’t violate the guidelines, rather than list them as passing the compliance test, I’ve indicated that they did not fail the test. Although in previous posts with test results I’ve listed games that “passed” the guidelines test, I’m no longer using that terminology. That designation could too easily be misinterpreted to mean that such games will definitely not cause seizures.
Even if a game doesn’t fail the guidelines compliance test, there is still a risk of seizures, for several reasons:
- I may not have tested a portion of the game with problem image sequences
- The guidelines aren’t fool-proof. They are designed to prevent seizures in approximately 97 percent of people who have photosensitive epilepsy, the condition where visual stimuli can trigger seizures.
- Many environmental and personal health variables–such as lack of sleep or illness– can affect an individual’s vulnerability to seizures
Do you need to worry about seizures from video games?
- The vast majority (97 percent) of people diagnosed with conventional epilepsy can play video games without risking a seizure because–unless their EEGs indicate otherwise–their seizures aren’t triggered by visual effects. These people don’t want others questioning their fitness for gaming.
- People with no history of epilepsy may be most at risk. Seizures can be triggered by flash and flicker even in people with no history of seizures, which means that many don’t know they are at risk of having a visually triggered seizure until a video game brings on their first event. Of the children who had seizures during the 1997 Pokémon cartoon broadcast in Japan, only 24% had previously experienced a seizure.
- Visually triggered seizures typically begin between ages 2-18, and most commonly begin around age 12-13. Of patients age 7-19 who seek medical attention for a seizure, ten percent test positive for photosensitive epilepsy. Researchers estimate that only 25 percent of people outgrow the condition, typically in their twenties.
- It is relatively unusual but not unknown for these seizures to develop in adults. Because in many individuals a number of factors (for example, emotional state and hormone levels) affect seizure vulnerability, a seizure may not actually occur until several of these factors are present simultaneously. Even one seizure can be life-changing if it results in injury or permanently bars an individual from certain occupations.
- It is also possible to experience subtle seizures and not realize they happened. This doesn’t mean there are no seizure consequences, though. Typically after seizures one’s physical, cognitive, and emotional functioning can be impaired.
More on the guidelines and how games are tested for seizure risk
None of the five video games picked by a Forbes reviewer as the year’s best first-person shooters meet safety guidelines for reducing the risk of visually triggered seizures.
The fast-moving, flashing images in these five games could provoke seizures in people whose seizures are triggered by visual stimuli, due to a sometimes hidden condition called photosensitive epilepsy. I tested image sequences from these popular games using software designed for checking the adherence of images sequences to the seizure reduction guidelines. All five failed:
Game developers could — should — use this same technology to build products compliant with the guidelines! The application I used to test the games for compliance isn’t a consumer product; it’s intended for developers. Instead of building games that comply, many developers simply place seizure warnings on games and consoles. People with no history of seizures don’t pay much attention to seizure warnings, though. Why would they?
Reason #1 consumers don’t know they may be at risk
Photosensitive epilepsy most often develops in adolescence and remains hidden until it’s activated by particular stimuli and circumstances. If earlier in life visual stimuli didn’t trigger an event, how does one know that’s no longer true?
According to one study, 74 percent of individuals with photosensitive epilepsy first learn they have the condition when they experience a seizure in the presence of flashing lights or another visual stimulus. This study was based on the histories of hundreds of children who had seizures during a 1997 Pokémon cartoon broadcast in Japan.
Sometimes the first seizure triggered by a video game can have life-changing consequences. A Navy pilot who played Oblivion, had a seizure that produced injuries and resulted in permanent loss of his flight clearance. Think of the medical testing he underwent before he was trained to fly–obviously his seizure vulnerability had not yet developed.
Reason #2 consumers don’t know about their risk
Some seizures aren’t noticeable. This means that included in the 74 percent who (think they) never had a prior seizure, there are some people who may already be experiencing them without realizing it. Subtle seizures involving no body movement may not draw the attention of others nearby, either.
People with no history of seizures aren’t aware that undetected seizures exist and therefore may dismiss any unusual physical or mental sensations while gaming. If the seizure causes a loss of awareness for a few seconds, the person will not be “present” at that moment to recognize what’s happening or remember it later. For more on undetected seizures, see the section “Research shows people often don’t detect their own seizures” in this post.
Note that undetected seizures as well as more obvious events can bring on a range of disabling physical and cognitive after-effects and mood changes that can linger for days.
Not all video games violate the image safety guidelines. Even though video games typically carry seizure warnings, the warnings don’t reflect the seizure risk of any particular game. Unfortunately, consumers have no way of knowing which games are in compliance and which are not.
Let’s say you’re an informed consumer, aware that some games can pose a seizure risk and you’d prefer not to take that risk. You understand that a game with lots of bright flashing is more likely to be a problem, but you can’t really know whether a specific game that you want to play is more likely to trigger seizures. How can you play only games that meet guidelines and avoid only the noncompliant ones? (This is where the testing I can do can identify certain cases of noncompliance.)
- The vast majority (97 percent) of people diagnosed with conventional epilepsy can play video games without risking a seizure because their seizures aren’t triggered by visual effects. These people don’t want others questioning their fitness for gaming.
- Want to know more about how I test video games? About the image safety guidelines? Read here.
- For the record, Forbes states that opinions of contributing writers (such as this guy who picked the five games) are their own, not the magazine’s.
What do a pineapple playing tennis and a grape going for a ride have in common? Two things: 1) They’re currently appearing in Google’s Olympics-themed iOS and Android Doodle Fruit Games app, and 2) viewing them in Google’s video promoting the app could give you a seizure.
For the next two weeks while the game app is available, Google is promoting it with a zippy, fast-paced trailer. Visitors watching the trailer see rapidly moving images images that could provoke seizures in anyone with a condition known as photosensitive epilepsy. I tested the trailer for its risk of inducing seizures and found two segments–involving the aforementioned pineapple and grape–with a flashing effect that could trigger photosensitive seizures. From what I can tell, the problem images appear only in the trailer and not in the games app itself–unless they appear only after players achieve a high score that I didn’t reach.
What is photosensitive epilepsy?
Photosensitive epilepsy is more common than is generally known, and researchers agree it is probably underestimated. People with the condition have epileptic seizures triggered by lights or images that flash faster than three times per second.
It gained some notoriety after a Pokémon cartoon shown on Japanese TV in 1997 sent nearly 600 children to emergency rooms with seizure symptoms. The condition had already been extensively studied and researchers had drawn up guidelines for reducing the seizure risk from video images, but at the time Japan did not protect TV viewers from problem images.
Who is affected by photosensitive epilepsy?
The vast majority of those with “regular” epilepsy are not affected by visual stimuli. But photosensitive epilepsy may be harder to detect and is underrecognized by the public and by doctors. You may be susceptible to photosensitive seizures and not even realize it since:
- Photosensitive epilepsy typically doesn’t develop until adolescence.
- It can occur in people with no history of seizures. Of Japanese children affected by the Pokémon cartoon, 76 percent had never before experienced a seizure.
- People with other forms of epilepsy are routinely tested for photosensitive epilepsy, but the condition may be most common in individuals who don’t have any other type of seizures. These people are very unlikely to be screened for it.
You can already be experiencing seizures and not know it.
- Not all seizures involve complete loss of consciousness, falling, or body movement observable by others. Such major events, known as generalized seizures, occurred in less than half of the Pokémon-affected children.
- Because consciousness is altered at the time, a person having a seizure often has no memory of it.
Even if you have no visible symptoms of a seizure, there can be lingering after-effects that include fatigue, sleep, learning, and memory problems, mood irregularities, among others.
How the media and entertainment industry can reduce seizure risk
More than 20 years ago, researchers studying photosensitive epilepsy defined the factors, in particular the flash frequency, that are most likely to provoke visually induced seizures.The UK has required all TV content to conform to seizure-reduction guidelines since 1994, and Japan enacted similar regulations following the Pokémon incident. To date, no other countries have done this, but a United Nations-affiliated agency did adopt recommendations for reducing photosensitive seizure provocation from television. Meanwhile, of course, interactive media have become a much bigger part of our lives than television, and the same guidelines for reducing seizures from TV should be adapted to the internet.
The World Wide Web Consortium (WC3), the international group that produces website accessibility standards for all types of applications, now includes guidelines for reducing the risk of visually triggered seizures. But incorporating such standards into private industry applications and sites is a hugely complex and time-consuming process.
The United States Department of Justice has been considering since 2010 the complexities of creating regulations ensuring access by the disabled to public and private websites. The DOJ announced this spring that rules governing private websites have been delayed until 2018 at the earliest.
In 19901, after a few consumer lawsuits were filed due to seizures, game developers began including a seizure warning that has kept consumers from filing or winning such lawsuits. Although most game documentation and packaging contain a seizure warning, not all games contain seizure-provoking visuals. Consumers don’t know which games actually have potentially harmful sequences and largely ignore the warnings.
How you can prevent photosensitive seizures
If you’re susceptible, even a brief exposure of a few seconds to flashing can be enough to bring on a seizure. If you know that you are vulnerable to these seizures, there are some precautions doctors recommend to avoid being triggered:
- When possible, avoid situations and stimuli that are likely to be provocative, including emergency lights, electronic billboards, video games, light shows, flickering fluorescent lights, fireworks, animé and other fast-moving cartoons
- Wear blue-colored glasses, which filter out the most provocative light frequencies. Most opticians can make these inexpensively.
- In the presence of flashing light, cover one eye.
- Increase your distance if possible from the flashing image–so, for example, stay at least 6 feet from your TV screen, and don’t play video games up close.
- Don’t play when fatigued or sleep-deprived.
- Take frequent breaks during prolonged exposure–although this won’t always help if you are triggered in a matter of seconds.
Testing for visuals that can provoke seizures
I tested the trailer using an industry-standard application called the Harding Flash and Pattern Analyzer that detects image sequences that can trigger photosensitive seizures. It is based on algorithms devised by Graham Harding, one of the world’s leading experts on photosensitive epilepsy. The application is widely used by producers and networks in the UK—including by the BBC—to reduce the risk of seizures from material on broadcast TV. The analyzer examines video sequences frame by frame for very specific and measurable image qualities that researchers have found can trigger seizures.
Seizures from video shown on TV about 2012 Olympics logo
This is not the first time that Olympics-themed promotional visuals have placed viewers at risk of seizures. A promotional video for the logo of 2012 London Olympics logo shown on British TV news in 2007 resulted in seizures in some viewers. It had not undergone the required testing that would have alerted producers to the problem prior to broadcast.
According to a Reddit post, a game that I’ve said “passed the seizure test” triggered a seizure. Recently the same game—Hearthstone—could have been implicated in a professional gamer’s seizure that happened during a live stream. What’s going on?
I write about games I’ve tested to alert readers to the games that don’t meet internationally recognized image safety guidelines. But I don’t want to create undeserved confidence that a game that passed the seizure test will be safe for anyone with photosensitive epilepsy.
Ian Hamilton, a user interface designer who specializes in and advocates for game accessibility, clarifies the role of testing this way:
“Passing the Harding test doesn’t mean that a game is safe. It means ‘reasonably safe’ because common triggers have been avoided. Something that gets a ‘pass’ can still absolutely cause seizures.”
I regularly write that your experience may differ, that I’m not trained in quality assurance, that I test excerpts of game play, and that health and lifestyle variables affect every individual’s vulnerability to seizures at any given time. Still, the meaning of my findings could be misleading without an understanding of the limitations of the seizure test itself:
- the pass/fail guidelines aren’t expected to prevent seizures in all individuals
- the test was designed for TV images, not video games
What the Pass/Fail guidelines mean
The guidelines originated in 1994, when the UK’s agency for regulating TV broadcasting (now known as Ofcom) inserted into its code of standards some technical guidelines to accommodate viewers with photosensitive epilepsy. These guidelines, based on studies of photosensitive epilepsy and consultation with Prof. Graham Harding and other photosensitive epilepsy experts, detail flash rates and spatial patterns that typically trigger seizures in people with photosensitive epilepsy. Specifications regarding saturated red images were added later, after the 1997 Pokémon incident in Japan.
Some compromises in the guidelines were made for the sake of practicality. Criteria for acceptable images (commonly referred to as the Harding test) were developed with the understanding that they would realistically protect most individuals with photosensitive epilepsy, but not all. For example, the guidelines permit images that flash at a rate of up to 3 times per second because flash at that frequency affects only 3 percent of photosensitive individuals. UK regulators decided that was “an acceptably small risk.”
The introduction to the guidelines states that their purpose is “reducing the risk of exposure to potentially harmful stimuli.” It also concedes that even when broadcasting images that comply with the guidelines,
“it is…impossible to eliminate the risk of television causing convulsions in viewers with photosensitive epilepsy.”
Applying TV guidelines to video games
There are no formal guidelines for reducing the seizure risk from video games. A 2005 consensus paper by experts on photosensitive seizures acknowledges that additional work would be required first on the existing guidelines for TV. In the meantime, it is reasonable to use the television guidelines since the impact of screen images on the visual system is the same.
The biggest challenge in applying TV specifications to video games is explained in the consensus paper:
“These principles are easier to apply in the case of fixed media (for example, a prerecorded TV show), which can be analyzed frame-by-frame. Interactive media, such as video games, may afford essentially limitless pathways through the game, depending on user actions. Therefore …in the case of video games, the consensus recommendations apply to typical pathways of play but cannot cover every eventuality of play.”**
Reducing risk going forward
In sum, a game that fails the Harding test is best avoided by those with photosensitive epilepsy. A game that passes is less likely to act as a trigger. Despite all the qualifiers, I believe there’s value in reminding people that seizures can happen to anybody, that certain video games can trigger them, and that you can lessen the risk by selecting games without lots of flash and patterns. Other strategies to lessen the risk of photosensitive seizures can be found here and here.
Tip of the hat to Ian, who suggested that I avoid the word “safe” when describing games that have passed the test. I also will be revising my prior posts to do some rewording.
Gamer’s seizure on live stream
Here’s a reminder that seizures can happen to anyone. A professional gamer known as Lothar had a seizure recently during his live feed while playing Hearthstone on Twitch. Lothar apparently has no history of seizures and the seizure may or may not have any connection to Hearthstone. In updates about his condition and hospital stay, Lothar didn’t mention photosensitive epilepsy nor has he said he’s been advised to limit his gameplay.
For the record, Lothar is also a body builder—he’s obviously a guy who has enjoyed good health and takes good care of himself. Lothar has a large and caring following and has been receiving lots of well wishes as he recovers. Why do I mention this incident here? Viewing the incident (you can find it on YouTube) and seeing how it affected so many fans who care about him reinforced for me the seriousness of seizures and the importance of preventing those that are preventable.