With an eye condition called Adie's Pupil, one of my eyes is fully dilated at all times, making sunglasses a necessity in any daytime outdoor condition. I took a chance on Fittys, and they are exceeding my expectations. The lense quality seems excellent, the color is dark enough to decrease my discomfort, and because they are a bit bigger than my glasses, they block more light than my custom-made clip-on sunglasses. I try to keep things simple, so I didn't like switching between prescription shades and glasses, my custom wire clip-ons eventually got bent and then sloppy, and very few frame makers use the clever magnetic attachment that was once my favorite. I'm really excited to have found Fittys. They are lightweight and look lots better than I thought they would.