I have light sensitive eyes, and usually find web pages too bright. I did adjust the brightness on the monitor itself, but part of the problem is also caused by the colors sometimes being too "hot" for my eyes. Over time I have come across similar complaints from others here at WP. It took me a while, but I found several browser add-ons that are supposed to help. The one I have been using is called Color That Site! And yes, the exclamation point is part of the name. I am not sure of the web address string for it, but just plug it into any search engine to find it. This add-on lets you change the colors of the different page elements of almost any site. You can change to a different color, or make a color lighter or darker. You can do just the one page, or for the whole site that the page is part of. It takes a little tinkering to get used the program, but it really helps my sensitive eyes.
Hope this helps others here! 
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If a man does not keep pace with his companions, perhaps it is because he hears a different drummer.
Let him step to the music which he hears, however measured, or far away.--Henry David Thoreau