Flicker Rate or Flashing Content (MS PowerPoint)
If elements in a document flash too rapidly, this can trigger seizures in people who have epilepsy. For this reason, flashing or flickering elements should be avoided in PDF documents.
Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz. (U.S. Section 508)
Make sure that PDF documents do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds. (Level A) (WCAG 2.0 – Level A)
Note: Since any content that does not meet this success criterion can interfere with a user’s ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.
The Purpose of this checkpoint is to prompt the user to verify that there are no flickering elements in the document.
CommonLook Office alerts the user to the presence of any elements that could cause flickering such as animated GIFs or scripts.
This checkpoint is relevant to the following regulations, guidelines and standards:
|Section 508 – 2001 Regulations (USA)||2001||“Web-Based Information & Applications”||(j)|
|W3C WCAG 2.0||2008||Web Content||Guideline 2.3.1|
|Health and Human Services – HHS (USA)||2013||PDF File 508 Checklist||ID 1.7|
|ISO 14289 (PDF/UA)||2012||PDF Technology||Section 7.1|