...
Click File in the top left corner of the document or presentation you are checking for accessibility. An Info screen will appear.
Click the Check for Issues box.
In the drop-down menu that appears, click Check Accessibility.
An Accessibility Checker menu will appear on the right side of the screen that lists any accessibility issues in the document.
Click on each of the listed issues. The issue will be highlighted in the document.
Fix each issue according to the description instruction provided until all issues are resolved.
...