Cuatro razones por las que las capas de accesibilidad no funcionan

En 4 Reasons Why Accessibility Overlays Don’t Work se explican cuatro razones por las que las capas de accesibilidad no funcionan:

1. Accessibility overlays need to be found and activated
   For an accessibility overlay to even begin to be effective, the user must first be able to activate it. Occasionally, the activation and deactivation methods for accessibility overlays are not keyboard accessible, meaning only a mouse can turn them on and off. This design leaves mobile and keyboard-only users unable to access the overlay at all.
   
   Some overlays also can’t be found by screen readers and other assistive technologies. As a result, users relying on those technologies will not be able to find the overlay, rendering it useless.
2. Accessibility overlays may not be compatible with the user’s preferred settings
   People with disabilities usually have their own preferred assistive technologies to help them perform tasks. For example, a user with low vision who uses a screen magnifier probably uses that same screen magnifier when browsing any website and can turn it on and off easily.
   
   Accessibility overlays, however, have their own predefined actions and functions. They do not conform to the user’s preferred technologies and settings. In the example of the user with low vision, this user must figure out how to turn on and configure the overlay’s magnifier tool rather than being able to use the already-configured preferred tool.
3. Accessibility overlays are not universally consistent
   The incompatibility of accessibility overlays with individual user settings might not be as much of a problem if accessibility overlays were universally consistent. However, accessibility overlays created by different companies must each be used differently as well.
   
   Companies should not burden their customers with figuring out how to use each new accessibility overlay. Instead, company websites should be built to conform to current web and accessibility standards. These standards empower all users to access and navigate the website using their preferred devices.
4. Accessibility overlays can’t detect most accessibility issues
   To make a website accessible, a wide variety of criteria must be evaluated across the entire site. Some of these can be automatically evaluated, such as color contrast. However, many items must be evaluated manually to be fully tested.
   
   For example, automated testing can determine if all images across the website have alt tags or if any are missing alternative text. Unfortunately, automated testing cannot determine if the text within each tag is appropriate for each image or not, which is where accessibility overlays fall short and manual testing is required.
   
   Automated testing can usually detect about 20-30% of accessibility issues, meaning accessibility overlays can only detect and address 20-30% of issues. This leaves 70-80% of accessibility issues completely undetected, never mind remedied, posing a significant legal risk to your company.