What is Visible Light used for? Why?

-The Obvious, allowing Humans to see Things -Its also used for Optical Fibres [Send Data over long Distances] -They simply Bounce the Light off the Sides inside the Narrow Core that takes the Light to the Place -Telephones, Internet Cables and Medical Purposes use Optical Fibres, and on the Medicine side, it just needs a Small Hole, instead of needing a Major Surgery