Comparison between the method of determining the power and axis of the cylinder by the Jackson cross cylinder technique and the bi-cross cylinder method as re-developed by Robert Vaughn

Abstract

The purpose of this study is to compare two methods of determining the axis and power of the far cylinder: the Jackson Cross cylinder and the Bi-Cross cylinder techniques, in an effort to determine if the Vaughn Bi-Cross cylinder technique could be substituted for the Jackson Cross cylinder test.