Large flashing content is present
A page MUST NOT contain content that flashes more than 3 times per second unless that flashing content is sufficiently small, and the flashes are of low contrast and do not exceed general flash thresholds.
Flashing or strobe-type effects in videos, graphics, or animations can put some people — those with photosensitive epilepsy — at risk for seizures. To be on the safe side, you should consider eliminating ALL flashes. However, small flash areas or very low contrast flashes may be acceptable from a seizure perspective, even though they are still likely to be annoying and distracting, which can be an issue for people with attention deficit disorders or cognitive disabilities.
Fix this issue by using ONE of the following techniques:
- Ensure that no content on the screen flashes more than 3 times per second.
- Ensure that content that flashes more than 3 times per second is sufficiently small: smaller than a contiguous area of 21,824 sq pixels (any shape).
- Ensure that content that flashes more than 3 times per second has a low enough contrast.
All three of the above techniques can be measured by a tool such as The Trace Center's Photosensitive Epilepsy Analysis Tool (PEAT).