photochromatic option

[bifocal eyeglasses]

I have both types.. one takes over 5 minutes to react and is NOT acceptable... the other goes dark in seconds.. less than 20 seconds.
I'm wondering if your photochromatic option is the quick modern technology.

[rimless glasses frames]

At our company,the transition lense react very fast,normally in less 15 secs.
You can take a try.