The Mudcat Café TM
Thread #152565   Message #3570697
Posted By: GUEST,Ed T
28-Oct-13 - 06:35 AM
Thread Name: BS: The history of everyday things
Subject: RE: BS: The history of everyday things
I believe that photochrome auto-tinting eye glasses reduce UVA and UVB rays. They seem to work better now than when they came out many years ago. I suspect the chemicals used react more quickly? The early versions did not react quickly when light conditions changed quickly

An interesting recent term used in the eye glass sector is digital bifocals, which don't seem to have much to do with the word at all?.