How can animation or flashing content cause issues?

Flashing or strobing content can trigger seizures in people with photosensitive epilepsy-a serious medical event, not mere discomfort. WCAG requires no content flash more than 3 times per second. Additionally, motion can cause vestibular issues-dizziness, nausea-for some users.

Safe animation practices: No flashing over 3Hz. Subtle motion preferred-avoid rapid, large-scale movement. Ensure first frame is meaningful for clients that don't animate (Outlook). Consider reduced-motion preferences-though email client support is limited. Avoid autoplay of anything distracting.

Animation should enhance, never harm. The goal is attention and delight, not medical emergencies. If you're unsure whether animation is safe, err conservative. A static image never causes seizures. And remember: effective animation is usually subtle-aggressive movement often looks spammy anyway.