a. [ Cf. F. périscopique. ] Viewing all around, or on all sides. [ 1913 Webster ]

2. of or relating to a periscope{ 2 }. [ 1913 Webster ]

Periscopic spectacles (Opt.), spectacles having concavo-convex or convexo-concave lenses with a considerable curvature corresponding to that of the eye, to increase the distinctness of objects viewed obliquely. [ 1913 Webster ]