second uniblock 10 x similarly attached to the other lens since it is attached to a frame 24 x that surrounds the other lens a bridge 56 connects the uniblocks 10 and 10 x fig9 is an exploded perspective view from below showing the manner in which the structure is assembled a screw 30 is inserted from below to secure the closing block fig1 shows an embodiment of a uniblock 10 y applicable to an auxiliary lens 16 it shows a portion forming a housing for a magnet 14 adapted to secure an auxiliary lens in superimposed relation to a primary lens and a portion forming a part of a closing block 22 for securing the uniblock 10 y to one of the auxiliary lenses 16 fig1 is an exploded perspective view showing the structure from below including a screw 30 that secures the closing block 22 fig1 shows the combination of an upper eyeglasses uniblock 50 comprising a portion forming a housing for a magnet 14 adapted to secure an auxiliary lens 16 in superimposed relation to a primary lens and a portion 22 a forming a part of a closing block 22 and a lower eyeglasses uniblock 52 comprising a portion forming a housing for the magnet 14 and a portion 22 b forming a part of the closing block 22 the upper and lower uniblocks 50 52 being joined together in superimposed relation to form a composite structure in this case the structure is applied to an auxiliary lens fig1 shows the cooperation of a primary lens 18 a uniblock associated therewith.