Nosepiece for eyeglass frames, which comprises: - a plate provided with a front face, intended to abut against the nose of a user, and with a rear face; - an appendage, which is projectingly extended from the rear face of said plate; - mechanical retention means adapted to fix said appendage to the frame of eyeglasses; characterized in that said mechanical retention means comprise at least: - a cup fixed to said frame of eyeglasses according to a first longitudinal extension axis provided with at least two opposite lateral walls, joined together by at least one connection wall and with two aligned first through holes extended along a second transverse axis, substantially orthogonal to said first longitudinal axis; said appendage comprising a convex portion delimited by at least two faces with a second through hole aligned with said first through holes along said second transverse axis; said second through hole being tapered starting from said faces towards the interior up to a substantially median narrowing thereof; said appendage being at least partially housed within said cup with said faces facing the lateral walls of said cup and being susceptible of rotating with respect to said cup around said second transverse axis with the surface of its convex portion in contact and in sliding-with-friction relation with the internal surface of said at least one connection wall, in order to maintain said plate in the angular position reached around said second transverse axis; - and at least one screw engaged in the first through holes of said cup and having a shank (70") placed to traverse said second through hole of said appendage, the latter being susceptible of rotating with respect to said cup around said first longitudinal axis with the surface of its convex portion in contact and in sliding-with-friction relation with the internal surface of said at least one connection wall, in order to maintain said plate in the angular position reached around said first longitudinal axis. - a plate provided with a front face, intended to abut against the nose of a user, and with a rear face; - an appendage, which is projectingly extended from the rear face of said plate; - mechanical retention means adapted to fix said appendage to the frame of eyeglasses; - a cup fixed to said frame of eyeglasses according to a first longitudinal extension axis provided with at least two opposite lateral walls, joined together by at least one connection wall and with two aligned first through holes extended along a second transverse axis, substantially orthogonal to said first longitudinal axis; said appendage comprising a convex portion delimited by at least two faces with a second through hole aligned with said first through holes along said second transverse axis; said second through hole being tapered starting from said faces towards the interior up to a substantially median narrowing thereof; said appendage being at least partially housed within said cup with said faces facing the lateral walls of said cup and being susceptible of rotating with respect to said cup around said second transverse axis with the surface of its convex portion in contact and in sliding-with-friction relation with the internal surface of said at least one connection wall, in order to maintain said plate in the angular position reached around said second transverse axis; - and at least one screw engaged in the first through holes of said cup and having a shank (70") placed to traverse said second through hole of said appendage, the latter being susceptible of rotating with respect to said cup around said first longitudinal axis with the surface of its convex portion in contact and in sliding-with-friction relation with the internal surface of said at least one connection wall, in order to maintain said plate in the angular position reached around said first longitudinal axis.