I very recently thought I might have permanently damaged my eyesight. I was working from a library, and stood to start closing up for the day. As I started to close my laptop, the screen (hi, glossy MacBook Pro) directly reflected the sun behind me. For the next 15-20 minutes a significant portion of my vision in both eyes was wavy. I could still safely drive home, thankfully, but it was a severe distraction. While I…
As a kid, I really loved focusing a magnifying glass on pieces of wood to burn them, without eye protection obviously. I haven't had any noticable problems because of it, but I do kinda wonder if it didn't cause a bit of damage.
A magnifying glass produces a small point of heat, with fairly low temperature and area. Many people in history have worked glass with no eye protection without serious consequences, other than cataracts perhaps (many older Italians still do not wear didymium glasses, much less the ones with welding shades).