The Aplanatic lens, a proprietary design of ESCHENBACH, offers the best optics available in magnifiers. The aplanatic lens is made of a high-quality PXM® lightweight lens system consisting of two plano-convex lenses that give a clearly defined, distortion-free image. Because of the edge-to-edge distortion free optics, this lens design is especially useful for patients with macular degeneration. Features: Magnification: 2.9x. Diopter: 7.4D. Lens Size: 75 mm. Lens Type: Model: 2668-75. Case Material: Leather. Mount: High Grade Plastic. Lens Material: PXM with Cera-Tec Coating. Weight 3 oz.