1. Method of calibrating an ophthalmic lens drilling machine, the said machine comprising: a drilling tool; an ophthalmic lens support associated with a first coordinate system; and programmable means for guiding the tool, which are associated with a second coordinate system expressing command coordinates which define a target drilling point, in which method the following successive steps are carried out: a template is placed on the support, the template having pre-applied markings defining a third coordinate system related to the said template, such that the third coordinate system is made to substantially coincide with the first coordinate system; and the template is drilled in at least one pre-determined point corresponding to a target point defined by predetermined command coordinates, such that a real drilling point is obtained, this method being characterized in that the following steps are then carried out in succession: an image of the template drilled in this way is created; the said image is analysed by image analysis means, so as to measure the offset between the position of the real drilling point and the position of the target pointy; and the guidance means are programmed so as to introduce a correction of the command coordinates capable of compensating for the said offset.