Knowledge in Lenses
Fresnel Lens
A Fresnel lens is a type of composite compact lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses. It has been called "the invention that saved a million ships.
Arun Thomas
Bifocals
Bifocals are eyeglasses with two distinct optical powers. Bifocals are commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism.