A method for acquiring and computing geometrical data of at least one pattern associated with an ophthalmic object , such as a presentation lens, an ophthalmic lens or a template for manufacturing ophthalmic lenses similar to the object or complementary thereto, the method being of the type in which a device (12; 112) for acquiring and computing geometrical data is used, said device comprising: - a transparent support adapted for bearing an ophthalmic object; - on one side of the support, means for illuminating this support; - on the other side of the support, a video camera oriented towards the support and adapted for producing a video signal representative of at least one pattern associated with the ophthalmic object laid on the support; and - signal processing and analysis means receiving as input the video signal produced by the camera, and adapted so as to compute and provide geometrical data intended for making the lens, the method being characterized in that : (a) a verification pattern independent of said geometrical data is traced on the ophthalmic object , this verification pattern being asymmetrical relatively to each of two axes perpendicular to each other; (b) the ophthalmic object is positioned on the transparent support of the acquisition and display device ; (c) by means of said device , said verification pattern is optically captured and analyzed; and (d) from the analysis of the verification pattern, the face of the ophthalmic object on which rests the ophthalmic object positioned on the support is determined, said device (12; 112) containing information representative of standard images of said verification pattern for each of the ophthalmic objects and for each of the possible positioning modes of these ophthalmic objects, and in that step (c) is carried out by means of the device in the following way: - (c1) correcting the orientation of the image of the ophthalmic object. - (c2) optically recognizing said captured verification pattern; and - (c3) comparing the captured verification pattern with said standard images. - a transparent support adapted for bearing an ophthalmic object; - on one side of the support, means for illuminating this support; - on the other side of the support, a video camera oriented towards the support and adapted for producing a video signal representative of at least one pattern associated with the ophthalmic object laid on the support; and - signal processing and analysis means receiving as input the video signal produced by the camera, and adapted so as to compute and provide geometrical data intended for making the lens, (a) a verification pattern independent of said geometrical data is traced on the ophthalmic object , this verification pattern being asymmetrical relatively to each of two axes perpendicular to each other; (b) the ophthalmic object is positioned on the transparent support of the acquisition and display device ; (c) by means of said device , said verification pattern is optically captured and analyzed; and (d) from the analysis of the verification pattern, the face of the ophthalmic object on which rests the ophthalmic object positioned on the support is determined, - (c1) correcting the orientation of the image of the ophthalmic object. - (c2) optically recognizing said captured verification pattern; and - (c3) comparing the captured verification pattern with said standard images. <EOS>