Is there any plugin for web browsers like Firefox or Chrome, which will automatically process CSS sheets to change page colors to be darker?
For example, if there is white or light background on website page, it could replace it with dark gray or other colors so it will be much less stress to my eyes.
I am asking because I have such a problem with my eyes. If there are such plugins, I believe, I could work better and longer. Manually editing CSS is the last thing I will ever try to do as it is easier for a plugin to accomplish this task.