A system for securing a patient eye at a known position in an external coordinate system is disclosed. The system includes a head support for supporting the patients head, an eye-contact device including a concave contact surface adapted to be placed against the front surface of a patients eye, and a port in fluid communication with the contact surface, by which a vacuum can be applied to the device to remove air between the eye and the contact surface, to stabilize the position of the eye with respect to the contact device, and a biasing mechanism operatively connected to the contact device for biasing the contact device against the eye with a force sufficient to the hold the contact device against the eye, when the eye is stabilized with respect to the device by removal of air between the eye and the devices contact surface.
