57192
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45758792-57192
Posi Hex Plgr, Stl, 1/2-13, Del Nose, PK5
the angle at which a display can be viewed with acceptable visual performance.
Lenses are classified by the curvature of the two optical surfaces. A lens is biconvex (or double convex, or just convex) if both surfaces are convex. If both surfaces have the same radius of curvature, the lens is equiconvex. A lens with two concave surfaces is biconcave (or just concave).