Objective observation optical material

摘要

An objective observation optical material comprises a sheet material composed of a plurality of spot-like transparent portions and an opaque portion and each of the spot-like transparent portions is formed into a circular shape having preferably a diameter of 0.7 to 2.0 mm or substantially a polygonal shape (including one whose sides are curved arcuately) inscribing or circumscribing such circle. The spot-like transparent portions are arranged to scatter in uniformly arranged positions so as to form connected regular triangles or squares whose sides are for example in the range from 2.0 to 5.5 mm.