An optical measurement apparatus comprises an optical system (100). The optical system (100) comprises a source (102) and an image capture device (112). The source (102) is arranged to generate, when in use, a beam of electromagnetic radiation. Further, the optical system (100) is arranged to direct the beam of electromagnetic radiation to a location to be measured (132). The optical measurement apparatus also comprises a feedback arrangement (400, 602, 604) arranged to receive a reflected beam from the location to be measured and to provide feedback information in response to receipt of the reflected beam, the feedback information being indicative of degree of alignment of the location to be measured with the optical system.