Pitfalls to Creating Accessible Content
Blinking and Flickering
- Flicker in the range 2Hz to 55Hz may cause seizures in people with
photosensitive epilepsy. The frequency of flicker (image appearing and
disappearing) in animated GIF's, Flash or other objects must be less
than 2 Hz or greater than 59 Hz.
- For comparison, the caret blink rate (or cursor blink rate) in Windows
2000 varies from 1/2 Hz at the slowest setting to 3 Hz at the fastest;
the middle setting is about 1 Hz.
Examples of pages with blinking and moving elements
Pop-Up Windows
