Photocromatic Glasses

Photocromatic Glasses

All plastic photochromic lenses as listed in the aforementioned table are constructed of diethylene glycol bis, usually referred to as CR-39, that is a trade mark of PPG Industries. Since the activated color of the spirooxazine derivatives used to make these photochromic lenses is blue, these lenses will assume the blue color when subjected to…

Photocromatic

Photocromatic

The lenses darken around 20% faster and lighten indoors around doubly fast as past Zeiss photochromic lenses. With the photochromic stuff dispersed in the cup substrate, the amount of darkening depends upon the thickness of cup, which poses issues with variable-thickness lenses in prescription glasses. With plastic material lenses, the material is typically embedded into…