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Digital Accessibility and Physical Reactions

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Ensuring that everyone, regardless of their physical or cognitive abilities, can access and use online content is not just a matter of inclusivity; it’s also a health, legal and ethical responsibility. One aspect of digital accessibility that deserves special attention is the risk of triggering seizures and physical reactions in individuals with photosensitive epilepsy and other physical conditions. Why is it important and how can we help to minimise this barrier.

Teddy bear in bed with thermometer and plaster Physical Reactions

Photosensitive epilepsy is a condition where seizures are triggered by specific visual stimuli, such as flashing lights, rapid changes in contrast, or patterns. These seizures, known as photosensitive epileptic seizures (PSE), can vary in intensity and duration but often occur suddenly, with little warning. Individuals with this condition are vulnerable to experiencing seizures when exposed to certain digital content, making it crucial to address this issue in the realm of digital accessibility.

Other people suffer other reactions to movement on websites.  One issue that is common is the effect of parallax on people.  That is when objects that are further away on a screen seem to move in a different direction to objects that are closer to the person.  If the objects are moving at different speeds, it can cause physical reactions such as nausea and vomiting.  A good example is car sickness.

A person holding a sign with the words, Digital Accessibility, in a blue circle.         Solutions

  • Avoid Flashing Content: One of the primary triggers for photosensitive epilepsy is rapidly flashing content. Designers should refrain from using flashing or strobing animations, especially those with high contrast, to reduce the risk.

  • Use Safe Animation Techniques: If animations are necessary, ensure they comply with accessibility guidelines. Use smooth transitions and avoid quick, repetitive movements that could trigger seizures.

  • Provide Warnings: For content that might inadvertently trigger seizures, such as videos or animations, provide a warning at the beginning. This allows people to make an informed decision about whether to proceed.

  • Offer User Controls: Allow users to control the speed of content playback, the ability to pause or stop animations, and the option to adjust contrast settings. These features empower users to customize their online experience.

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Regularly testing digital content for accessibility is essential. Automated tools can help identify potential issues, but manual testing is often necessary to catch nuances that automated tests might miss. Compliance with accessibility standards, like Web Content Accessibility Guidelines, is a key benchmark for ensuring your content is safe for all users.


Digital accessibility is not just about making content available to a broader audience; it’s about creating a safe online environment for everyone. Preventing seizures and other physical reactions in individuals is a vital aspect of this effort. By adhering to accessibility guidelines, designing with inclusivity in mind, and providing user-friendly features, we can ensure that the digital landscape becomes safer and more welcoming for all users, regardless of their unique needs and challenges.