What do you think about the possibility that people develop weaker eyesight from regularly being exposed to light that is too bright/too intense?

Old wives' tale: Extremely bright light (staring at the sun even a few seconds) or strong UV exposure (e.g. hours on a sunny ski slope) can damage the retina. However, it is an old myth that "eyestrain" -- bright lights, watching TV, reading in dim light -- weakens vision, e.g. raises the need for eyeglasses in the future. It's nonsense. Use sun glasses in bright sun but otherwise don't worry about it!