^ Yes, me too, I wear shades even if it's cloudy. My eyes are very sensitive. The sunlight is the worst, but snow is also bad and when it's windy, my eyes start swelling and tearing immediatly. When I look into a bright light or flash, I see it for more than a minute after it's gone and dark again. There are days when I even have troubles reading because my eyes are swollen and hurt and they get tired soon. I have bright blue eyes and I have been dealing with this kind of issue for years now. Imagining all the flash lights Bono has to look into so many times I don't have any problem believing the "story". If you look closely on many pictures you can clearly see his right eye swollen and red. I don't think it's "bullshit" at all.
But, of course, there's part vanity, too, and it's just a part of his image and his public persona now.