OPTICAL FILTER, APPARATUS EQUIPPED WITH THIS FILTER, EYEGLASSES LENS, HEAT RAY ABSORPTION FILTER AND OPTICAL FIBER

摘要

An optical filter having a color similar to an achromatic color efficiently cuts near-infrared rays and allows the user to perceive a hue almost the same hue of natural light. An apparatus equipped with such an optical filter, a glasses lens, a heat ray absorption filter and an optical fiber are also disclosed. The optical filter is characterized in that copper ions (II) are contained in the synthetic resin and the saturation is 0 to 12. The optical filter is characterized also in that copper ions (II), metal ions and/or a colorant capable of absorbing light of a wavelength of 450 to 600 nm are contained in the synthetic resin, and the saturation is 0 to 12. The metal ions and the colorant preferably have an absorption peak at a wavelength of 500 to 550 nm, and are particularly preferably cobalt ions (II).