Image Number 2 for United States Patent #5846457.
The invention relates to a light-absorbing contact lens and process for preparing same. A contact lens is tinted with colorants which provide desired spectral transmittance characteristics over the tinted portion of the lens. The contact lens provides transmittance of incident radiation having a wavelength from 500 to 700 nm which is variable and wavelength-dependent. The lens of this invention also preferably filters out ultraviolet and blue light (wavelengths from 200 to about 500 nm). Various transmittance patterns for wavelengths from 500 to 700 nm are obtainable by appropriate choice of colorant combinations; the transmittance curve in this region and the colorants to achieve the desired transmittance characteristics are chosen to fill particular needs of a wearer as for example limiting transmittance of visible light in high intensity light environments. Lenses according to the invention may provide unique benefits for use with particular applications such as sporting activities, recreational activities, or the like. Both hard and soft contact lenses are disclosed, and various examples of specialized lenses for particular applications are disclosed.
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