Screen movement is a frequent technique used today to get people to interact with web content. There are various forms of screen movement for the web including animations, flashing content, user video controls, and slideshows. Flashing content is also a commonly used type of screen movement that provides focus to various elements in a page. When screen movement is present within a webpage, it is crucial that screen movement is developed in a way that makes it accessible to all users.
Provide Controls to Moving Content
When screen movement is present on a web page, a mechanism should be provided for users to control the blinking such as a stop/pause buttons. Elements such as a slideshow, presentation or video, must contain user controls to play, pause or stop the motion or video. This will ensure users have control over the screen movement, should they find it too distracting.
When adding screen movement to your website, it is crucial to avoid content that flashes or blinks excessively. For example, web pages should not contain anything that flashes more than three times during a one-second period. Anything that flashes too excessively runs the risk of inducing seizures.
Types of screen movement to avoid
To ensure accessibility, blinking, scrolling and rotating screen movement should be avoided at all cost. Movement of this kind could be a distraction to users and makes it difficult to read and process information. Avoid using the following types of screen movement elements that are known to cause uncontrolled movement:
- HTML Blink: The blink element (<blink>) is used to create text to appear and disappear text at an uncontrolled rate.
- CSS Blink: CSS Blink tag is the CSS “text-decoration: blink;” code. This tag also causes uncontrollable blinking.
- Marquee Element: The marquee element is a non-standard HTML element that causes text to scroll up, down, left or right automatically.
Why is it important?
Although the overall goal of screen movement is to appeal and engage users to a website, when not used properly, screen movement can cause distraction and can be a problem for users with disabilities. Excessive screen movement with no mechanism to control can make it difficult for users to gather information. Users with visual processing or cognitive disabilities, who may need more time to read and process the information, will encounter accessibility barriers if there is too much movement on a web page. Moreover, when excessive screen movement such as blinking, flashing, and scrolling is used, there is a risk that this may trigger seizures, dizziness or nausea to individuals prone to them.