Photochromic properties in high index glass...

[drk]

Since I've only relatively recently learned that photochromic properties can vary in plastic high index materials, does the same principle apply to high index glass materials?

To wit: a patient is not as "photochromically happy" with his 1.6 glass Varilux Comfort PGX vs. his crown SV PGX. Does he have a point?

[QDO1]

try this link - there is a lot of difference - there are charts denoting the difference in this document

http://www.norville.co.uk/pdfs/part2.pdf

[drk]

Nice link, friend.

[fjpod]

Since I've only relatively recently learned that photochromic properties can vary in plastic high index materials, does the same principle apply to high index glass materials?

To wit: a patient is not as "photochromically happy" with his 1.6 glass Varilux Comfort PGX vs. his crown SV PGX. Does he have a point?

In addition to differences in photochromic properties of different kinds of glass, there is the difference in how the glass is hardened...chemically or case hardened(heat). If I remember right, case hardened photogrey gets darker outside, but stays darker indoors.