There may be features builtin to your Linux operating system as well, but as far as Firefox is concerned '''Blind''' and '''Low Vision''' would be '''Accessibility''' features and would be in an extension. Look through your extensions for those four words alone or in combination. In Windows they would be in the windows control panel under Accessibility Features now called "Ease of Access Center" and there are "high " and "optimize for blindness" within. I tried Google search for '''linux blind OR low.vision''' but looks like the links probably point to much larger articles and your purpose is not to set it up but get rid of it. But you mentioned Outlook and there are options in Outlook: :Google search: '''"Use blind and low vision experience" firefox linux outlook''' <br><small>Please mark "Solved" one answer that will best help others with a similar problem -- hope this was it.</small>