Comment: People with cognitive of visual disabilities may have trouble processing information on the screen fast enough to read the content if it is flickering. Further, movement can cause such distractions that reading the rest of the material may be difficult or impossible.
Screen elements that flicker in the proscripted range can trigger epileptic seizures in visitors with a susceptibility to such seizures.
<img>, <object>Comment: If you insist on using elements that flicker or blink, you cannot assume that user agents (browsers) have a mechanism that controls that behavior for those users vulnerable to the adverse effects.
Therefore, you must provide some way to turn off the effect yourself in a clear, easily-identified way.
<img>, <object>STANDARD 5.3 The use of the blink element is prohibited.
Comment: In addition to being extremely annoying to your visitors, the blink element also can cause seizures in sensitive individuals.
<blink>