There was a time when a car stereo only had one knob to control the sound coming through the speakers: volume. Eventually, stereo makers designed systems which allowed the listener to tune the sound to their liking with frequency control options and more.
The next evolution came in the form of presets. Listening to rock? There’s a preset for that. Jazz? Here you go.
In much the same way, sunglass lenses have evolved past the three basic colors of grey, brown and G-15 (Green). These essential colors are certainly not obsolete, but for those that want optimal vision for a specific activity there are now new and exciting lens colors and coatings to choose from.
In order to better comprehend the innovative new options, let me explain how sunglasses work at the most basic level.