I have this extension on both firefox and waterfox browsers. On firefox it has begun to block all images, but not on waterfox, both using identical Font Contrast settings.

I could be mistaken, but I think the "Form Border" option is only available via the options button in the address bar (popup panel). It's missing when accessing the settings through the addon manager. I think I'm using the latest version of the extension. My machine runs Firefox 56.0.2 64-bit on Windows 7 64-bit platform. The issue could be with my outdated version of Firefox - which I deliberately don't want to upgrade. Aside from that, this extension is absolutely awesome! Love the toggle on/off option.

UPDATE 07/04/2020:

This is a second review unrelated to my first. I wanted to make a suggestion. In the options, the word "dims" is a little ambiguous. I wonder if you might change the text of your hover help tip for "ADVANCED MODE" to read: "Darkens text to a deeper shade of its color instead of black"? then maybe label the "BRIGHTNESS %" option below "DARKNESS %" instead? Maybe it's just me, but using "DIMS" in tandem with "BRIGHTNESS" is perplexing. Love the addon otherwise!

Good extension, but needs more refinement in performance area. It freezes FF for several seconds, turns pages loading very slow. Blacken is better for now.

Nice little add-on, but a bit limited. Can only target grey text and not less-contrast text of other colors. Does not deal with text that are too small, or link colors. I'd suggest the "Text Legibility" addon instead.

It does seem to solve the problem of the idiotic light fonts on light background, which 20 year olds with excellent eyesight think is cool. I await the day they can't read a page because of their own code. One problem, though. The icon is right next to the URL and before the "bookmark this page" icon, and is apparently unmovable. I'd rather have it over with my other addons, which I keep to the right of the search bar. Right now it's cluttering my address bar.

Can be useful add-on for some pages, but is it possible to add 2 options?
1. to hide icon in the address bar (since Quantum not allowing additional toolbars, two icons for one add-on is now too much);
2. to set maximum font size (or exclude header tags?), so add-on don't alter big colored header lines, which make the whole page look unpleasant. Thanks.