OptiSource is a leader in the OPTICAL tinting industry, using cutting edge technology to produce chemically SUPERIOR dyes. The use of dye stabilizing chemistry produces FAST absorbing dyes that provide consistent colors from bottle to bottle and lens to lens. OptiSource's top performing dyes are available in 4 oz. concentrated bottles. Our super-concentrated dyes are both non-toxic and biodegradable. These are same great dye colors you have grown to love. Available in 46 high fashion colors.