Systems and methods for analyzing the anatomy of a patient's eye with circular or rotated polarized laser beams, or with laser beams of different wavelengths are disclosed. One system includes a polarization beam-splitter and a quarter-wave plate, wherein the quarter-wave plate is configured to circularly rotate a laser beam received from a laser that is transmitted and passes through the polarization beam-splitter, and to transform a circularly rotated back-reflected beam to a linearly polarized laser beam that is perpendicular to the beam that was transmitted through the polarization beam-splitter. Substantially all of the back-reflected beam is directed to a photo-detector for analysis. A Faraday rotator subsystem may be substituted for a polarization beam-splitter. An optical system including a laser that generates a laser beam of a first wavelength for therapeutic treatment, and another laser that generates a laser beam of a second wavelength for measurement is also disclosed.