During the Transit of Mercury a few years ago, an Astronomy professor on campus had telescopes set up. Some were set up to project an image through the viewfinder onto a white sheet, and some had filters over the lens to view it directly. I wanted to try this with my own refracting telescope, and I swear one of the filters he was using was simple aluminum foil. Problem is, I can't find ANY info. out there on whether this is safe or not.
There are things that happen in chemistry that are, well, sort of unexpected. Likeexplosions. NOT your explosion, but the guy across the lab table or next to you. The glass beaker explodesglass (hot glass with acid in it) goes flying across the room. Do you know where it's going to land? YepYOUR EYE. Or someone decides they want to see what a little bit os sodium metal would do in a beaker of water. OUCH! Ever seen water burn? OK it's not the waterbut if it pops and blows a little bit of sodium metal out and it lands in your eyeit'll just keep on going..into your eye. INTO your eye. this will give you an idea of what kind of glasses you might want. I can tell you this, some people wear head shields in chemistry labs. Covers the whole face! And have safety glasses on under that and regular glasses under that! A nice blast injury to your face with lots of little pock marks from the little tiny glass pieceslooks ridiculous too.
Light? He supposedly invented the bifocals to improve eyesight. Also he invented the Franklin Stove which improved radiant energy (light?).
