Photochromic ophthalmic lens of organic materials

摘要

An ophthalmic lens made of organic material has at least one layer of photochromic mineral glass within its mass to impart photochromic properties to the lens. This layer has a fibrous structure and may comprise a piece of woven fabric produced from fibres of photochromic mineral glass possessing a refractive index and a coefficient of chromatic dispersion which are equal to those of the constituent organic material of the lens.