Cylindrical lens is used to correct astigmatism in the eye, and, in rangefinders, to produce astigmatism, stretching a point of light into a line.They are available in either plano concave or plano convex configurations. Plano-Concave Cylindrical lenses have a negative focal length and are used for image reduction or to spread light. Plano-Convex Cylindrical lenses have a positive focal length, which makes them ideal for collecting and focusing light for many imaging applications. Plano-convex cylindrical lens,plano-concave cylindrical lens,bi-convex cylindrical lens,bi-concave cylindrical lens,meniscus cylindrical lens,long cylindrical lens,special cylindrical lens etc.. Specifiction of our cylinderical lens as follow: *Material BK7 or other optical materials *Dimension Tolerance +0.0 -- -0.1mm *Center Thickness +/-0.1mm *Focal Length Tolerance+/-1% *Surface Quality:20/10 *Surface Figure lambda/2 at 633nm on plano side *Clear Aperture >90% *Chamfer 0.25mm at 45 degree typical *Coating Optional