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(a) The Eilean Glas Light (1907): Lighthouse lens which makes use of the Fresnel Principle to focus the beam. Photograph taken by Dr. Oscar Quevedo-Teruel at the Science Museum of London; (b) Original Hyperbolic lens: D = 190 mm, F = D/4 = 47.5 mm and t = 29.5 mm; (c) Discrete coordinate transformation of the original shape; (d) Dielectric constant distribution for the new coordinate space.
