Time to replace the spherical equivalent with the average paraxial lens power

A scalar measure of refractive power is frequently used to evaluated outcomes. Such measures are based on the average a lens or system, for example, spherocylinder. commonly has been mean spherical equivalent usually referred as (SE). Harris recognised, however, that there may be other terms SE.1 As such, it recently shown ![Formula][1] which in addition orthogonal rays, includes oblique paraxial rays. It also associated with better visual acuity than SE and therefore more clinical use.2 The relationship between ![Formula][2] SE, needs clarification. There currently two methods calculate lens: Consider following system F … [1]: /embed/mml-math-1.gif [2]: /embed/mml-math-2.gif