I am 90% blind and want to create a site for the Blind & Visual Impaired.

1. I was wondering if anyone knew of how to do this so that a reader can click a Toggle to increase or decrease the content font size while the screen resizes to fit their monitor's edges so that they do not need to scroll across to read the text?

2. I want to create a large button the the to of the page next to the reize screen toggle which when clicked will reverse contrast and was wondering how I might do this?

Please let me know if there are any plugins to do these things.