\Per`i*scop"ic\, a. [Cf. F. p['e]riscopique.]
Viewing all around, or on all sides.
{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.