A lot of au)s)c children are riveted by the
mo)on of (fan) blades… Dyslexics who can
see the blade ﬂicker say it's horribly
fa)guing and distrac)ng.
The mo)on is part of the aCrac)on, too.
…I do get stuck on those geometric screen
savers a lot of computers have.
Guidelines for Avoiding Seizures
• No more than 3 ﬂashes per second.
• The combined area of ﬂashes occurring concurrently
occupies no more than a total of one quarter of any 341 x
256 pixel rectangle anywhere on the displayed screen area
when the content is viewed at 1024 by 768 pixels.
—The Trace Research & Development Center, a part of
the College of Informa)on Studies at the University of
1999’s stringent standards re: anima4on
• Provide alt text for animated GIFs.
• Synchronize your cap)ons/audio descrip)ons.
• “Ensure that moving, blinking, scrolling, or auto-upda)ng
objects or pages may be paused or stopped.”
• A note about ﬂashes and epilepsy (plz keep ﬂashes below
20 per second, thanks).
Broad generaliza4ons/good guesses
• Anima)on should serve a purpose.
• Be consistent
• Downgrade to fades
• Use mo)on blur on fast, large moving elements
• An)cipate and signal oncoming anima)ons
• Reduce autoplay
• No one likes parallax anymore
Issues facing standardizing accessibility
• Extrapola)ng from unrelated research.
• Research from homogenous sources.
• Humans are inherently diﬀerent.
It appears every user with Ves)bular
disabili)es is unique and its hard to nail
down a group of provoca)ve ac)ons that
would signiﬁcantly address a lot of the
issues without signiﬁcant impact on
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