An eye contact device and assembly for stabilizing a human eye at a selected position in an external coordinate system is disclosed. The device includes an eye-contact member having an inner contact surface for contacting a front surface of an eye, and a vacuum port formed within the eye-contact member by which a negative pressure can be applied between the eye and the contact surface, to stabilize the position of the eye with respect to the device. The device, which is adapted to be biased against the patients eye, to secure the device to the eye, may be pivotally coupled to a positioning arm, and may carry one or more beam-directing elements by which the position of the device in an external coordinate system can be determined.
