An apparatus (1) for treating an eye using a laser beam includes a first light source (6) for producing a therapeutic laser beam (7), a second light source (8) for producing an alignment beam (9), and control means (2, 3, 4, 10) for controlling the first and the second light source and for directing the therapeutic laser beam and the alignment beam onto the retina (13) of the eye (12) being treated. According to the invention that the control means (2, 3, 4, 10) are arranged to control the second light source (8) and to direct the alignment beam (9) onto the retina (13) of the eye (12) being treated in such a way that the alignment beam forms a visual message (17) onto the retina as a function of at least one operational property of the therapeutic laser beam (7).