There is a nice thunderstorm in action, over my house, right now. That reminds me of another thunderstorm; one that caught me out on the bike.
I was on the way home from work, and a storm was brewing. I had on my rain jacket and neoprene booties, in case it rained, but I wasn't wearing my safety glasses. I often do wear lab glasses when riding in rain or snow, because my prescription lenses are too small to protect my eyes from the raindrops.
This particular day, though, I had forgotten to change out of my regular glasses. As it started raining, I figured I might as well just keep my head and pedal on. I hate stopping, when I don't have to, especially in the rain.
I ride in a mountain bike helmet when I commute, despite the Bike Snob's opinion on that. In the Fall and Spring, I use the visor to shield my eyes from the sun, and it helps keep precipitation out of my face. I figured I could hide under it, in the rain, and keep the water out of my eyes.
Then, the hail started falling. It was small, and relatively soft hail; the kind they call "Graupel". I just kept riding. Small hail, like that, is no real problem. It's no problem until one of the little hailstones nails you right in the eye, which is precisely what happened.
The hailstone managed to make it past the edge of my visor, and go between my glasses and my brow, then hit the top of my eyeball. Thankfully, it hit the part of my eye covered by the lid, at the time. Otherwise, it might have actually injured me. As it was, it hurt like hell.
I stopped, at that point, and put on the stupid safety glasses. I'm a slow learner, but I do learn.