Light filters using yellow melanin and melanin-like oligomers and photochromic dyes

摘要

Selective fractionation and separation of melanin and use of fractionated or separated melanin in connection with light filters is disclosed. Further, light filters that use yellow melanin or melanin like materials prepared to have a yellow color and a melanin transmission spectrum in combination with a photochromic dye are disclosed. The yellow form of melanin has minimal impact on the perception of light intensity with transmission values greater than 80%. The combination allows for a single light filter suitable for both night driving and sunglass applications and which also preserve color perception.