Accessibility on the web can be particularly tough. The browsers and the technology behind the web itself weren't designed with accessibility in mind. But that doesn't mean it can't be done. Google has several efforts to improve accessibility on the web and in its apps.
Its Google Apps suite has been getting several improvements and updates focused on this problem, which Google is now showcasing.
In Google Calendar for example, Google has worked on improved focus handling and better keyboard access and navigation.
Google's OCR technology, already used in Docs, is now being put to good use making scanned PDF documents and images accessible via screen readers.
Google is also improving access to its mobile apps, the Gmail and Google Drive apps for both Android and iOS have better "explore-by-touch" features as well as the ability to navigate via a keyboard/trackpad, where available. Here's a more complete list
of the improvements.