Abstract: The invention concerns a series of underwater vision articles comprising two optical elements (1, 3), two sealing elements placed in contact with the face via their right and left contact areas (2, 4), having the following characteristics: the optical elements are placed flatly on a plane on the side opposite the contact areas: P1, P2 represent respective points that are the lowest and to the furthest left from the inner edge (5) or outer edge (6) of the left contact area (4); P3, P4 represent respective points that are the lowest and the furthest right from the inner edge (7) or outer edge (8) of the right contact area (2). Independent of the size, the ratio between PP2,4 and PP1,3 is constant, and/or the ratio between, on the one hand, PP2,4 and a constant and, on the other, PP1,2 is constant or PPi,j is the distance between Pi and Pj for any i and j.

Abstract: The invention concerns a size-determining system and method of size grading type, used in particular to determine sizes, and a method to produce the system for a product to be worn on parts of the body. The method to produce the system includes selecting principal morphological parameters from among parameters corresponding to the distance between two morphological markers characteristic of the body part and selecting product parameters, determining an arithmetical relationship between each product parameter and the principal morphological parameters, and determining sizes defined by particular variation intervals of the principle morphological parameters or product parameters. The system stores values of the morphological parameters and product parameters and includes a module to calculate the value of the product parameters in relation to the value of the principal morphological parameters.

Abstract: The invention concerns a size-determining system and method of size grading type, used in particular to determine sizes, and a method to produce said system for a product to be worn on parts of the body, notably in the area of items for sub-aquatic vision. The method to produce the system comprises selecting principal morphological parameters from among parameters corresponding to the distance between two morphological markers characteristic of the body part. It also comprises selecting product parameters corresponding to the distance between two geometrically characteristic points of the product, determining an arithmetical relationship between each product parameter and the principal morphological parameters, and determining sizes defined by particular variation intervals of the principal morphological parameters or product parameters.

Abstract: The invention concerns a series of underwater vision articles comprising two optical elements (1, 3), two sealing elements placed in contact with the face via their right and left contact areas (2, 4), having the following characteristics: the optical elements are placed flatly on a plane on the side opposite the contact areas: P1, P2 represent respective points that are the lowest and to the furthest left from the inner edge (5) or outer edge (6) of the left contact area (4); P3, P4 represent respective points that are the lowest and the furthest right from the inner edge (7) or outer edge (8) of the right contact area (2). Independent of the size, the ratio between PP2,4 and PP1,3 is constant, and/or the ratio between, on the one hand, PP2,4 and a constant and, on the other, PP1,2 is constant or PPi,j is the distance between Pi and Pj for any i and j.