Why don my new glass photochromic lenses work as well as my old pair?
Glass photochromic lenses unlike plastic need to be worn and broken in unlike plastic photochromic lenses which have a life span of about 2.5 to 3 years. To speed up the break in period the lenses can be placed in the sun for the fist day or two allowing the sun and UV like activate the photochromic crystals and with use will get darker and change faster until they meet the manufacturers performance levels.
