The different types of eyeglass lenses that are available include polycarbonate, Trivex, high-index and aspheric lenses, notes WebMD. These lens types are made from different materials, such as thermoplastic, different plastics and glass. The first lens types were made from glass, but there were drawbacks to using these lenses, such as they were quite heavy and breakable.
The introduction of plastic lenses occurred in 1947, and these lenses were made from the plastic material known as CR-39. These lenses were lightweight and are still used today. The next lens material that became popular was polycarbonate, which was made by the Gentex Corporation in the 1970s. These lens types are impact-resistant and are made from a thermoplastic material. These lenses may be suitable for young children and can block 100 percent of UV light.
Trivex is a new type of lens that like a polycarbonate lens is impact-resistant and offers 100 percent UV protection. The differences between the two are that Trivex is a much lighter material and may provide good optic correction because of its high Abbe value, states All About Vision. The Abbe value is related to how well the lens can disperse wavelengths.
High-index plastic and aspheric lenses are two other popular lenses used today. High-index plastic lenses, which are very thin and lightweight, may be good choices for patients that require a very high prescription, reports WebMD. Aspheric lenses are manufactured so that the curvature of the lenses vary over its surface, giving it a thinner and more aesthetic look. Photochromic lenses, which change from transparent to a dark tint color, are other types of lenses available.