Accessibility Starts with Supporting Technology That Already Exists
Every operating system — whether it's Windows or macOS, Android or iOS — comes with built-in accessibility tools. These tools are an integral part of the OS itself. They are technologies that enable people with disabilities to use their personal devices just like anyone else: launching applications, reading documents, browsing the web, and carrying out everyday tasks.
When we design an accessible user interface, we must support the features our users already rely on — features built into the accessibility infrastructure that operating systems themselves provide.
High Contrast Mode? Your Interface Needs to Handle It
Consider a Windows user who has enabled High Contrast Mode (High Contrast Mode) – a built-in tool designed to help people with visual impairments. This feature is widely used, and when activated, the OS automatically overrides the colors of text and backgrounds to make them more readable and distinct.
But what happens when a website doesn't account for this?
Many websites — especially those that rely heavily on CSS background images as a core design element, simply disappear. When a background image is used as the foundation for displaying text or providing visual contrast — but vanishes entirely in accessibility mode — the user is left with a broken, unreadable, unclear interface that is sometimes completely unusable.
A concrete example:
In the first screenshot — an interface on a non-accessible site. All logos are rendered using CSS as background images rather than as an IMG tag
The moment High Contrast Mode is activated, a dark background that exists as an image (rather than a standard CSS color) disappears — and the light-colored text sitting on top of it becomes almost completely unreadable.
The takeaway: embrace the accessibility tools built into the OS
Instead of "fighting" the operating system – work with it. Give assistive technologies the place they deserve. Use HTML and CSS semantically and correctly. Don't rely on background images to convey critical information. Maintain clear hierarchy, ensure adequate contrast, and always test your website or system under different OS accessibility modes.
Real accessibility starts before the code
Accessibility isn't just about meeting standards — it's about deeply understanding how users perceive your interface. The better we understand the tools that help them, the better equipped we are to build products that genuinely respect them.