I just heard about the photochromic lenses, could you please explain the benefits for photochromic lenses? And could you please aslo advise their estimated prices both in the retail stores and online stores? Thanks for your help.

Photochromic lenses are clear indoors and darken automatically outdoors. They also are able to protect your eyes from 100 percent of the sun's harmful ultraviolet radiation. At the online optical stores, their price is aroud USD90.00; at the retail stores, their price is around USD150.00.