Back then when people thought radiation was basically a vitamin, they crammed it into everything from face masks to toothpaste (Radium girls gives it a thumbs down), optics manufacturers weren't far behind (but hey, at least in their case it actually did something useful, Jiří Zouhar gives it a thumbs up).

What better way to start than with one of the most legendary lenses in history, first introduced all the way back in 1900? The name Heliar is such a prized family heirloom that it has survived to this day and is still in production - though now for digital cameras (I am crossing myself). However, it must be...