Hardware Self Contained, Closed Products

Checkpoint 5.2: Screen flicker

Avoid causing the screen to flicker with a frequency greater than 2 Hz and less than 55 Hz.


Displays which flicker or flash can cause epileptic seizures in susceptible individuals, particularly if the flash has a high intensity and is within certain frequency ranges. This includes flashing text, turning graphics on and off or repeatedly changing between different images on the screen.

Required development techniques

The following technique is the minimum required to meet Checkpoint 5.2 from the IBM Hardware Self Contained, Closed Products Accessibility Checklist:

Do not have the screen flicker with a frequency between 2 Hz and 55 Hz.

Recommended development techniques

The technique above is required; the following techniques are recommended to enhance accessibility:

Required test techniques

Test the hardware to ensure that it complies with accessibility requirements.


Software test cases are needed to test this checkpoint.


The following technique is required to verify this checkpoint:
Action Result
1. Verify, through code inspection, that there is no flicker with a frequency greater than 2 Hz or less than 55 Hz. Pass:


©2009 IBM Corporation

Last updated September 01, 2009.