A patient interface includes an eye interface device, a scanner, a first support assembly, and a beam source. The eye interface device is configured to interface with an eye of a patient. The scanner is configured to be coupled with the eye interface device and operable to scan an electromagnetic radiation beam in at least two dimensions in an eye interfaced with the eye interface device. The scanner and the eye interface device move in conjunction with movement of the eye. The first support assembly supports the scanner so as to accommodate relative movement between the scanner and the first support assembly parallel so as to accommodate movement of the eye. The beam source generates the electromagnetic radiation beam. The electromagnetic radiation beam propagates from the beam source to the scanner along an optical path having an optical path length that varies in response to movement of the eye.