A method of identifying optical surfaces in an eye for performing laser surgery on the eye, the eye including a cornea having anterior and posterior surfaces, a lens capsule having anterior and posterior surfaces, an iris, and a limbus, the method comprising: coupling the eye to a laser eye surgery system that includes an optical coherence tomography imaging subsystem, the OCT imaging subsystem including a reference path length that is adjustable so that a distance from the laser eye surgery system to a detection window of the OCT imaging subsystem is adjustable, the OCT imaging subsystem employing a detection beam having a plurality of wavelengths such that the detection window spans a range of distances relative to the laser eye surgery system, wherein the laser eye surgery system is configured to employ an interface assembly (52, 58, 96, 184) that is removably mounted to the laser eye surgery system so as to be disposed between the OCT imaging subsystem and the eye; generating an OCT sample beam; focusing the OCT sample beam at a plurality of different locations within the eye, the plurality of different locations include at least two different distances from the laser eye surgery system, the different distances defining a depth range encompassing an expected variability of distance from the laser eye surgery system to the corneal anterior surface, to the lens capsule anterior surface, or the lens capsule posterior surface; and processing returning portions of the sample beam focused at the plurality of different locations to locate, relative to the laser eye surgery system, the corneal anterior surface, the lens capsule anterior surface, or the lens capsule posterior surface; characterized in that the interface assembly (52, 58, 96, 184) includes two or more reference features (125, 127, 182, 186); and further in that the method comprises using the OCT imaging subsystem to locate the reference features (125, 127, 182, 186) relative to the laser eye surgery system; and comparing the OCT based locations (CLa, CLp) of the reference features (125, 127, 182, 186) relative to predetermined positions (CLan, CLpn) of the reference features (125, 127, 182, 186) to determine at least one of that the interface assembly (52, 58, 96, 184) is properly mounted to the laser eye surgery system, that the interface assembly (52, 58, 96, 184) is improperly mounted to the laser eye surgery system, that fluid is present in the interface assembly (52, 58, 96, 184), that fluid is missing from the interface assembly (52, 58, 96, 184), an angular orientation of the interface assembly (52, 58, 96, 184) relative to the laser eye surgery system, or whether the interface assembly (52, 58, 96, 184) is coupled with a left or a right eye of a patient. coupling the eye to a laser eye surgery system that includes an optical coherence tomography imaging subsystem, the OCT imaging subsystem including a reference path length that is adjustable so that a distance from the laser eye surgery system to a detection window of the OCT imaging subsystem is adjustable, the OCT imaging subsystem employing a detection beam having a plurality of wavelengths such that the detection window spans a range of distances relative to the laser eye surgery system, wherein the laser eye surgery system is configured to employ an interface assembly (52, 58, 96, 184) that is removably mounted to the laser eye surgery system so as to be disposed between the OCT imaging subsystem and the eye; generating an OCT sample beam; focusing the OCT sample beam at a plurality of different locations within the eye, the plurality of different locations include at least two different distances from the laser eye surgery system, the different distances defining a depth range encompassing an expected variability of distance from the laser eye surgery system to the corneal anterior surface, to the lens capsule anterior surface, or the lens capsule posterior surface; and processing returning portions of the sample beam focused at the plurality of different locations to locate, relative to the laser eye surgery system, the corneal anterior surface, the lens capsule anterior surface, or the lens capsule posterior surface; characterized in that the interface assembly (52, 58, 96, 184) includes two or more reference features (125, 127, 182, 186); and further in that the method comprises using the OCT imaging subsystem to locate the reference features (125, 127, 182, 186) relative to the laser eye surgery system; and comparing the OCT based locations (CLa, CLp) of the reference features (125, 127, 182, 186) relative to predetermined positions (CLan, CLpn) of the reference features (125, 127, 182, 186) to determine at least one of that the interface assembly (52, 58, 96, 184) is properly mounted to the laser eye surgery system, that the interface assembly (52, 58, 96, 184) is improperly mounted to the laser eye surgery system, that fluid is present in the interface assembly (52, 58, 96, 184), that fluid is missing from the interface assembly (52, 58, 96, 184), an angular orientation of the interface assembly (52, 58, 96, 184) relative to the laser eye surgery system, or whether the interface assembly (52, 58, 96, 184) is coupled with a left or a right eye of a patient.