Reflectance values express the percentage of light that is reflected back from a surface, the difference having been absorbed or transmitted by the surface.
Definition of AXIAL. 1. : of, relating to, or having the characteristics of an axis.
Axial length of the eye | definition of axial length of the eye by Medical dictionary. http://medical-dictionary.thefreedictionary.com/axial+length+of+the+eye.