| 摘要 |
Individual lenses of subsidiary glasses, such as sun glasses, are attached to lenses of ordinary glasses by means of three fasteners, each in the shape of a square arch, made of synthetic resin and each provided, at about the middle of the arch, with an inner projection to form front and rear fitting portions at the front and rear sides of the projections respectively. The three fasteners are fitted respectively, with the front fitting portions, in three grooves provided in the periphery of the subsidiary lens and secured in place. The grooves are located so that lines connecting them form a triangle, with the distance between upper and lower fasteners located near the bridge of the ordinary glasses being larger than the outside diameter, in a vertical direction, of the ordinary glasses. This permits the lens of the subsidiary glasses to be fitted and removed from the lens of ordinary glasses in a direction transverse thereto.
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