Photochromatic lenses darken when exposed to the sun. Discover where these lenses came from, how they work and why they're commonly referred to as "transition" lenses in this episode of BrainStuff.
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

Why Is Siberia's Batagaika Crater Known as the Doorway to Hell?
11:10

BrainStuff Classics: How Would Authorities Handle a Murder in Space?
08:17

How Does Taste Work?
13:59