Usability and Accessibility
The blink element has been consistently criticised by usability and accessibility experts. In 1996 Jakob Nielsen described the element as "simply evil" in his Alertbox column Top Ten Mistakes in Web Design.
The World Wide Web Consortium's Web Content Accessibility Guidelines (WCAG) 1.0 state that content authors should avoid causing the screen to flicker or blink, noting that such effects can cause problems for people with cognitive disabilities or photosensitive epilepsy.
The German Federal Government's Barrierefreie Informationstechnik-Verordnung (Barrier-free Information Technology Ordinance) also states that flickering or blinking content should be avoided.
The United States Federal Government's Section 508 states that pages should avoid causing the screen to flicker with a frequency between 2 Hz and 55 Hz, a range which covers rapidly blinking text. This does not seem to apply to blink element itself, which blinks at frequency of 1 Hz.
To comply with the User Agent Accessibility Guidelines a user agent must either "allow configuration to render animated or blinking text content as motionless, unblinking text" or never blink text. Mozilla Firefox satisfies this requirement by providing a hidden configuration option to disable blinking.
Read more about this topic: Blink Element