ANSI Z80.20

Abstract

This American National Standard applies to contact lenses worn over the front surface of the eye in contact with the preocular tear film. The standard covers rigid intracorneal and haptic (scleral) contact lenses, as well as soft paralimbal contact lenses. Table 1 provides a high-level list of materials used for both rigid and soft contact lenses. <br><strong>Purpose</strong> <br>The purpose of this standard is to incorporate tolerances for all contact lenses in a single standard and to provide, as much as possible, for standards in development by the International Standards Organization (ISO) for rigid and soft contact lenses. <br>This standard is applicable for specifying (1) allowable tolerances; (2) measurement methods of parameters and properties important for proper functioning and manufacturing of contact lenses and (3) conformance criteria for tested product. The standard includes tolerances for single-vision contact lenses, bifocal lenses, lenses that alter the optical density and/or spectral composition of transmitted visible light (tinted or pigmented contact lenses, such as those with enhancing, handling, and/or opaque tints), and lenses that significantly attenuate ultraviolet radiation (UVR-blocking lenses). This standard covers lenses designed with spherical, toric, and conoidally aspheric surfaces, and recommended methods for the specification of contact lenses.