The European Patent Office has cancelled a patent (# 837087) that was restricting Degussa's use of its Trogamid CX polyamide material to the manufacture of clear lenses, eyeglasses and magnifying glasses. The same material can now be used to make also eyeglass frames, sunglasses and lenses for sports glasses. Trogamid CX7323 is a semi-crystalline polyamide whose crystallites are so small that they do not scatter visible light, providing 90 percent transparency, a refractive index of 1.516 and an Abbe dispersion rate of 45. Degussa claims that it is more resistant to stress and cracking than other materials, making it particularly well suited for mounting thin-rimmed and rimless glasses.