Variable-light transmittance article and method for preparing same

摘要

Variable-transmittance articles, such as an ophthalmic lens, are prepared by applying to or incorporating within the article a combination of two (or more) organic photochromic substances exhibiting different activated absorption maxima within the matrix in which the substances are incorporated. One organic photochromic substance has an absorption maximum within the range of between greater than 590 and about 700 nanometers. The other organic photochromic substance exhibits at least one absorption maximum and preferably two absorption maxima, within the range of between about 400 and less than 500 nanometers. The organic photochromic substances are used in a proportion to achieve a near neutral coloring of the article. The article may also be tinted with a light compatible tint (dye) to achieve a more neutral color when the photochromic substances are activated.