The anti reflective coating is designed to reduce the amount of light lost to reflection at the surfaces of individual, transmissive elements. Historically, motivation for the development of the anti reflective coating came from problems with loss of light and ghost images in compound, multi-element lens systems. They experience refraction as if they emanated from the object; however, since they were created inside the lens itself, they produce strange patterns in the image plane. Ghost images can be controlled in several ways, but application of the anti reflective coating accomplishes the task most effectively.