The Accessibility Checker is available only in Adobe Acrobat Pro - the paid version, not in the free version.
Open Accessibility Checker
- Open your document in Adobe Acrobat Pro
- Click on All Tools in the command bar
- Click on View More in the tools list
- Click on Prepare for accessibility
Run the Accessibility Checker
- Click on Check for accessibility
- Choose your options in the dialog box
- Click the Start Checking button
- Results will so in a panel on the right
- Click the arrow next to the category to see the issues
- Some things need to be checked manually like reading order