Module 2 Motion Sensitivity

Disorders in the inner ear Links to an external site. can cause dizziness, vertigo, nausea, and migraine headaches. These symptoms can be triggered by motion simulations and flashing graphics. Less common is the phenomenon of photosensitive epilepsy (PSE) Links to an external site.  in which seizures are triggered by visual stimuli such as flashing lights or moving patterns.

Interestingly, some of the biggest offenders in this area are high-tech companies like Apple Links to an external site., whose advertisements and user interfaces contain ever-more sophisticated visual effects. Problematic effects include:

• Flashing graphics
• Large areas of motion
• "Parallax" effects where foreground and background move at different speeds
• "Scrolljacking" in which the user doesn't have control over the presence or speed of screen scrolling
• Scrolling discrepancies, like huge horizontal shift when the user is scrolling downward
• Animations with a large amount of perceived distance

This article investigates the real-distance equivalents of the spring-physics "zoom" effects in Apple's iOS7. Links to an external site."iOS 7 doesn't just look different, it feels different: Every time you close an app to a folder, you're hurling it about 25 feet away from your face."

Designing Safer Web Animation For Motion Sensitivity Links to an external site. explores a number of sites and interfaces with problematic effects, and offers suggestions on how to minimize those effects in your content design.

Challenges and Solutions