A laser treatment unit for performing eye surgery, including a contact glass which can be placed onto the eye and through which a treatment laser beam (2) passes. A safety mechanism displaceably holds the contact glass such that the contact glass retreats when the contact glass is subjected to the action of a force contrary to the direction of incidence of the laser beam. The safety mechanism enables this retreating when a force is greater than a force limit value (Fmin) and holds the contact glass in a fixed manner when the force is less than the force limit value.
