Patent ID: 7884992
Filing Date: 2011-02-08
Classification: G02B,G02C

Abstract:
1. A photochromic optical article comprising: a substrate; and a photochromic coating coated on an outer surface of the substrate and having at least two photochromic layers, each of the photochromic layers having a composition that contains a carrier and at least one photochromic dye, the compositions of the photochromic layers being different from each other; wherein the photochromic dyes of the photochromic layers are the same, the carriers of the photochromic layers being the same, the compositions for the photochromic layers being different in weight ratio of the photochromic dye to the carrier; wherein the weight ratio of the photochromic dye to the carrier decreases from an innermost one of the photochromic layers that is nearest to the outer surface of the substrate to an outermost one of the photochromic layers that is farthest from the outer surface of the substrate.