Photochromic ophthalmic lens

US9625740B2 · kind B2 · utility

Assignee

• Essilor International (Compagnie Generale d'Optique) · FR

Inventors

• Amelie Kudla · Charenton-le-Pont, FR
• Hélène MAURY · Paris, FR

Key dates

• Filing date: Oct 10, 2013
• Grant date: Apr 18, 2017
• Expiry date: Oct 14, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G02C7/107
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A photochromic ophthalmic lens includes a photochromic substrate and a filter having at least one layer formed on the main front face of the lens. The filter has a total thickness ≦700 nm and the front face has: an average UVA reflection factor over a range of wavelengths from 330 to 380 nanometers that is ≦40%, for an incident angle between 0° and 15°, an average blue reflection factor over a range of wavelengths from 420 to 450 nanometers that is ≧5%, for an incident angle between 0° and 15°, a spectral reflectivity curve for an incident angle between 0° and 15°, the reflectivity curve having a reflectivity maximum at a wavelength <435 nanometers, and a width at mid-height ≧70 nanometers, and for an incident angle between 0° and 15°, Δspectral=1−[R0°-15° (480 nm)/R0°-15° (435 nm)], with Δspectral≧0.8.