Paragon Vision Sciences, Inc. Paragon Z CRT Paragon Z CRT

Paragon Z CRT contact lenses are manufactured from Menicon Z® (tisilfocon A). The lenses are designed to have congruent anterior and posterior surfaces each consisting of three zones: The central spherical zone, a mathematically designed sigmoidal corneal proximity “Return Zone" and a non-curving “Landing Zone”.The lens design also includes a convex elliptical edge terminus smoothly joining the anterior and posterior surfaces.Paragon Z CRT Contact Lenses for Corneal Refractive Therapy are to be worn overnight with removal during all or part of each following day. The lens material (tisilfocon A) is a thermoset copolymer derived from fluoro-methacrylate and siloxanylstyrene bound by crosslinking agents. The lenses for Corneal Refractive Therapy are available as lathe cut firm contact lenses with a light blue tint. The blue tinted lens contains D&C Green No. 6. A UV absorber (Benzotriazol) is added as an additive during the manufacturing process.