Mean of a sample of equivalent dioptric powers.
Keating's method for finding dioptric power is generalized to include compound optical systems. Other methods can not be generalized in this way.
Harris
W F
WF
Department of Optometry, Rand Afrikaans University, Johannesburg, South Africa.
D005139:Eyeglasses; D008433:Mathematics; D055095:Optics and Photonics