An understanding has grown over the years to make all kinds of computer-generated content available to people with disabilities. PowerPoint is no stranger to this accessibility concept, and has many options up its sleeve that help your slides be more relevant to those with accessibility impairments. Similar to how PowerPoint’s spell checker alerts you to potential spelling errors, the built-in Accessibility Checker highlights potential accessibility issues in your presentation so that you can fix these potential problems and make your content accessible to everyone.
Check accessibility options in PowerPoint 2013 for Windows.