Ophthalmic filter materials

摘要: An ophthalmic filter material having a photopic transmittance (Yp) higher than the scotopic (Ys), ratio of Yp:Ys being in range 2.0-4.0, dominant wavelength within ranges 580-605 nm and color purity 60-75 % whereby colors perceived through approximate those scene viewed. A method producing such which comprises heating photochromic glass lens reducing atmosphere for time at temperature that is sufficient to impart recited characteristics surface equivalent flowing hydrogen atmosphere, or immersing tintable plastic solution dye characteristics.