Blinking and animation
What do I need to do?
Avoid content that blinks, flickers or moves. If elements do blink, they should do so less than twice a second (2 Hz) or more than 55 times a second (55 Hz).
How do I do this?
Do not use <blink> or <marquee> because their effects cannot be controlled by most browsers. If possible, avoid animated elements altogether.
Why is this important?
Blinking elements on a Web page can cause seizures in individuals with photosensitive epilepsy, especially when the flashing is very intense or between 2 Hz and 55 Hz in frequency. They can also cause problems for those using screen readers and other devices.
