Patent ID: 7800759

Claim:
An axial eye length measurement apparatus for measuring an eye having a cornea and a second surface, comprising: a light source configured to produce a beam of partially coherent light; a beam splitter disposed in the beam and configured to project some of the light into a test arm and some of the light into a reference arm; a first mirror disposed in the reference arm to form a first reference path and configured to intercept a first portion of the light in the reference arm; a second movable mirror disposed in the reference arm to form a second reference path and configured to intercept a second portion of the light in the reference arm; a processor configured to control at least the second movable mirror such that a corneal interference peak formed using the first portion and the light in the test arm and a second interference peak formed using the second portion and the light in the test arm have a non-zero separation, wherein the processor is configured to control at least the second mirror such that the corneal peak and the second peak are separated from one another by a predetermined amount.