Accessibility overlays are third-party web scripts that alter the user experience. Providers, which include AccessiBe, Userway, AudioEye, and EqualWeb, sometimes claim that installing their script will prevent lawsuits in the U.S. under the Americans with Disabilities Act.

Read more at
https://www.accessibilitynewsinternational.com/you-cant-solve-accessibility-with-1-line-of-code/