According the U.S. Census Bureau, optical instrument and lens manufacturing consists of three distinct sectors. The first sector deals primarily with the manufacture of optical instruments and lenses such as telescopes, binoculars, standard scanning microscopes, and non-ophthalmic lenses. The second branch deals primarily with polishing and coating non-ophthalmic lenses. The third industry category is concerned with mounting non-ophthalmic lenses. Generally speaking, the optical instruments and lens industry is concerned with devices that gauge an optical property or measure or magnify an image, but doesn’t include the manufacture of ophthalmic lenses, such as eyeglasses.
Approximately one-third of sales in the optical instruments and lens industry is derived from devices used in defense operations, such as sighting and tracking components. The automobile and steel industry keeps optical test and inspection equipment in steady demand, which accounts for about seven percent of industry sales. An additional half of the industry’s sales are from miscellaneous devices, while binoculars and related devices only account for four percent of total sales, and microscopes an additional three percent. Many products offer compound lens systems or systems with multiple optical features.
In 2000, industry manufacturers consisted of two general categories: manufacturing companies that produced optical lenses and equipment, and manufacturing companies that produced sighting, tracking, and fire-control components. About two-thirds of the revenue came from the former, while the latter was responsible for the remainder. Because of the increase in military application demand, such as night-vision optics, that particular area of the market is expected to continue to grow. In 1997, such devices topped $404 million dollars.
The manufacturing process involved in creating lenses and other optical components primarily revolves around the grinding process. Before grinding, however, glass must be cut or molded into a crude lens form, and then it is ground using an abrasive agent (such as diamond) on a grinding wheel. Next, a softer abrasive like silicon carbide is used for fine grinding, and in certain instances a coating is applied to enhance optical traits.