Blinking Elements and Marquees

ISSUE:

Between 1 in 25,000 and 1 in 10,000 people have seizure disorders. Blinking page elements and marquees (text or images that scroll on the screen) can trigger a seizure in people with photosensitive epilepsy. Sensitivity to flicker increases with the intensity of the light and the portion of the person's visual field affected. In order to minimize the probability of inducing an epileptic seizure, screen elements that flicker or change should do so at a frequency of less than twice a second (2 Hz) or greater than 55 times a second (55 Hz). Blinking elements and marquees can also be problematic for persons using screen-readers, screen magnification applications or users with cognitive impairments.

STANDARD:

• An option shall be available that allows the user to disable or adjust the frequency of blinking screen elements.

Programmer's Note: Caret blink rate can be adjusted through the keyboard options in the Windows Control Panel. When the cursor blink rate is set to slow, the cursor will flash 1.2 times per second. The cursor blink rate will increase 100 milliseconds for each increment, up to a maximum of 5 times per second. The setting can be queried by calling GetCaretBlinkTime.

An option shall be available that allows the user to disable or adjust the rate at which screen elements scroll.