Some people with cognitive or visual disabilities can’t interact well or at all with blinking or moving objects on the screen. Movement will also sometimes make such a distraction that the rest of the page will be unreadable for those with disabilities. Plus because of certain disabilities some readers are unable to read moving text or be able to react fast enough to moving objects to interact with them.
Check Points:
7.1 – Until user agents allow the control of flickering screens don’t allow the screen to flicker. People with photosensitive epilepsy can have seizures caused by flashing screens.
7.2 – Until user agents allow users to control blinking don’t make content blink
7.3 – Allow users to stop and start moving content and avoid movement in the page. When content in a page moves make sure to provide a mechanism with in the script or applet to allow users to freeze any movement. Or use CSS to make it possible to turn on and off.
7.4 – Do not create periodically updating pages until user agents allow the option to turn it off.
7.5 – Don’t use markup to auto-redirect pages. Instead configure the server to redirect pages.
Note. The BLINK and MARQUEE elements are not defined in any W3C HTML specification and should not be used.
For more detailed information please refer to this link.