Question: 2 diopter is equal to?
Answer: Diopter strength refers to the optical power of a lens. Lenses with a focal length of 1 meter (about 39 inches) have a diopter strength of 1. Since diopter strength is based on the inverse ratio of the focal length, a 2 diopter lens is not 2 meters but 1/2 meter, a 3 diopter lens is 1/3 meter and so forth.