Epilepsy is a brain disorder that causes recurring, unprovoked seizures that can be triggered by certain stimuli. For people with photosensitive epilepsy (PSE), these triggers can include flashing lights, patterns, or anything that may cause a visual seizure.
Although epilepsy is the fourth most common neurological disorder in the world, there are still plenty of misconceptions surrounding the condition. By understanding the facts about common triggers and potential hazards of this disorder, we can understand how epilepsy fits into digital accessibility conversations. Let’s get started.
Myth 1: Epilepsy affects everyone the same way
Epilepsy syndromes can cause a variety of symptoms, and according to the Epilepsy Foundation, only about 3% of people with epilepsy have PSE triggered by specific light conditions.
In addition to seizures, epilepsy may cause temporary confusion, stiff muscles, uncontrollable movements, and psychological symptoms. While seizures are a classic symptom of the condition, having a single seizure doesn’t mean that you have epilepsy — and many people can control seizures with medication or surgery. Some people also outgrow seizures as they age.
But while PSE is rare, content creators have a responsibility to make websites as safe as possible for all users.
Myth 2: People with epilepsy are not impacted by digital accessibility
It’s true that most websites aren’t harmful for people with epilepsy, but some flashing or flickering content can be dangerous for folks with photosensitivity.
The Web Content Accessibility Guidelines (WCAG) are the international standards for digital accessibility. WCAG 2.1 Success Criterion 2.3.1, “Three Flashes or Below Threshold,” requires that web pages contain no content that flashes more than three times in any one second period, or that the flash is below the general flash and red-flash thresholds.
Here are a few quick tips for keeping your content within those rules:
- Avoiding content that contains rapidly changing images. Generally, this content isn’t helpful — and it may annoy all users.
- If content must flash, keep it below three flashes per second. If content absolutely must flash above that threshold, the content should be relatively small compared with the other content on the screen — below 25% of the user’s 10-degree visual field.
- If content must flash, provide a mechanism to stop the content before the flashing begins.
- Don’t create flashing content that uses fully saturated reds. The color red is intense and more likely to trigger photosensitive users.
We also discourage using autoplay for multimedia, which can create barriers for people with epilepsy, people who use assistive technology, and other types of users.
Myth 3: The ADA doesn’t apply to people with epilepsy
Epileptic syndromes may not change the way that people live or use the internet, so epilepsy is sometimes considered an “invisible disability.”
But epilepsy is still a significant condition, and the Americans with Disabilities Act (ADA) requires most digital content to be accessible to all users, regardless of their abilities or limitations.
Content that creates a physical reaction may certainly violate the ADA and other digital accessibility laws. Of course, organizations have other reasons to embrace accessibility: Eliminating autoplay and limiting flashing content can make content more appealing to all users.
Related: What is ADA Website Accessibility?
Myth 4: Epilepsy accessibility is all about flashing content
As we’ve discussed, flashing content can be dangerous for some users. However, there are other ways to make your content more useful for people with epilepsy:
- Ensure that your website has an appropriate semantic structure. This can make your content more useful for people who use reader modes, content blockers, and other technologies to remove potentially triggering content.
- Consider providing options to change font size and color.
- Make sure your website works predictably when scaled (zoomed-in) to 200%.
- Some types of epilepsy can affect the way that people process language. Write clear, concise content with descriptive subheadings.
These techniques will improve your content for all users — and by testing your website or mobile app against WCAG, you can expand your audience while providing every visitor with an accessible experience.
To learn more, download our free eBook: The Definitive Website Accessibility Checklist. For help with a specific accessibility issue, send us a message to connect with a subject matter expert.