Gradient photochromic lens and method selectively reducing photochromic activity
AssigneeAmerican Optical Corporation
InventorRichard J. Hovey
Life of this patent
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Abstract
A new gradient photochromic lens having a uniform resistance to fatigue is disclosed. A method for selectively reducing photochromic activity in one or more portions of a lens having a photochromic dye uniformly disposed across the surface thereof is also disclosed.
Claims14
An optical element exhibiting gradient photochromic response comprising:
- a synthetic plastic host,
- a photochromic spiroindolinenaphthooxine dye, said dye being dispersed uniformly across at least one element surface, an ultra-violet radiation absorbing material, said material being capable of inhibiting activation of said photochromic dye and said material dispersed in greater concentrations in selected portions of the element whereby photochromic activity of the dyed lens varies with the concentration of said material.
A gradient photochromic plastic lens having a uniform fatigue resistance which comprises:
- a synthetic plastic host,
- a photochromic spiroindolinenaphthooxine dye, said dye being dispersed uniformly across at least one lens surface,
- an ultra-violet radiation absorbing material, said material being capable of inhibiting activation of said photochromic dye and said material dispersed in greater concentrations in selected portions of the lens whereby photochromic activity of the dyed lens is not uniform.
A method of reducing the photochromic activity of a plastic lens containing a photochromic spiroindolinenaphthooxine dye dispersed uniformly across at least one surface, which comprises imbibing an ultra-violet light inhibiting material capable of blocking radiation which activates the dye.
Dependencies are inferred from the claim text.