Patent · US Expired

Photochromic ophthalmic lens of organic materials

US4300821A · kind A · utility

28Cited by
6References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 26, 1980
Grant dateNov 17, 1981
Priority date
Expiry dateFeb 26, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B1/041
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.