When we first built Office Online, we worked hard to make the suite accessible to blind and low vision users by using a new web accessibility standard called WAI-ARIA. While this web standard has allowed Office Online to be usable with a screen reader, we’ve made some further improvements over the past year to provide an even better experience. We are excited to talk about these improvements and have you try them out.
Read more at source: http://blogs.office.com/2015/01/09/new-accessibility-enhancements-office-online/
