Abstract: The invention relates to a mask (1) including a basic structure (2) and at least one screen (3). The basic structure (2) has at least four through-holes (8) in the receiving surface of the screen (3), each hole having, along the length thereof, at least two enlargements spaced apart from one another, forming chambers having a larger cross-sections than the hole, one of the enlargements being located at a greater depth in the hole (8) and the other enlargement being located at a shallower depth in said hole. The screen (3) comprises at least four fingers (12) projecting from the inner surface thereof, which are arranged in alignment with the holes (8) and which comprise a widened portion (12a) suitable for insertion in either said enlargements.

Abstract: Each lens frame includes a slit at the assembly area of the corresponding temple, delimiting two independent which can be moved apart to widen the lens frame so that a lens can be inserted or removed. Each temple is connected to the corresponding lens frame by a tenon, including a first part connected to the temple, for making a rotating connection between the tenon and temple along the longitudinal axis of the temple, and a second pivotable part engaged between the portions of the lens frame. This second part, has a first dimension that can be in a first angular position of the tenon, in which the two portions, are not separated, and a second dimension in a second angular position of the tenon, in which the two portions are separated sufficiently to widen the lens frame so that the lens can be replaced.

Abstract: Each lens frame includes a slit at the assembly area of the corresponding temple, delimiting two independent which can be moved apart to widen the lens frame so that a lens can be inserted or removed. Each temple is connected to the corresponding lens frame by a tenon, including a first part connected to the temple, for making a rotating connection between the tenon and temple along the longitudinal axis of the temple, and a second pivotable part engaged between the portions of the lens frame. This second part, has a first dimension that can be in a first angular position of the tenon, in which the two portions, are not separated, and a second dimension in a second angular position of the tenon, in which the two portions are separated sufficiently to widen the lens frame so that the lens can be replaced.