2.05.06 Colour usage: Flashing, flickering & blinking
Flashing, flickering & strobing content
As a minimum such images are distracting whilst trying to read the content. Animations and moving text are also considered distracting.
Visual effects that flicker or produce a strobe-like effect may cause seizures in some individuals.
Seizures induced by flickering or strobe-like effects are known as photo-epileptic seizures. Seizures can be dangerous. Don't be responsible for causing them.
Warning: Do not use the following link if you have any cause to believe that you may be adversely affected by strobing or flickering images. Example of an flickering images.
Do not use blink or marquee. These are not valid HTML and users cannot control them.
It is also worthy to note that two images flickering at two different rates may also cause seizures as the interaction between the two phases.