Abstract: Systems and methods orient sensors of an optical system that measures aberrations of an eye. The aberration measurement system may include an optical aberration sensor and an eye image sensor. An asymmetric feature can be imposed in an optical beam path so as to introduce artifacts at the sensors. The optical aberration sensor is often oriented relative to an eye image sensor in response to the asymmetric feature of an optical beam path. In some embodiments, a tool supported by a rail imposes the asymmetric feature on the optical beam path. Aberrations of the eye are measured along the optical beam path with an optical aberration sensor while an eye image sensor forms an image of a tissue structure of the eye positioned along the beam optical path. An aberration correcting shape is identified and ablated in corneal tissue with a laser.