What are the substances or chemicals that make sunscreens effective?
Visible light consists of many different wavelengths which are generally “mixed together” – so-called white light. When these wavelengths are split into “layers” by the prism effect of moisture in the atmosphere, the colors of different wavelengths are revealed and we see a rainbow. The shortest wavelength is at the bottom of the rainbow and produces the color violet. Below that wavelength the rainbow becomes invisible and seems to disappear. We call that invisible layer ultraviolet. It is the ultraviolet part of light energy that causes skin cancer and premature aging of the skin. Ultraviolet is the part of the rainbow that we cannot see with our eyes. Ultraviolet rays are a form of energy that comes from the sun. Without ultraviolet light life would not be possible. All of our plant life depends upon it. Ultraviolet light acts on our skin to produce vitamin D. But ultraviolet energy can also be harmful. Like visible light in which different wavelengths produce different colors, diffe
