What are the materials of lens blanks

The materials of lens blanks (i.e. raw materials for lenses that have not been processed into their final shape) are mainly divided into two categories: glass and resin, each with multiple specific materials. The following are common materials and their characteristics:

Glass lens blank: a traditional material made of optical glass, which has a high refractive index, excellent optical clarity, and scratch resistance, but is heavy and fragile, and is less commonly used in modern times. ‌

Resin lens blank: mainstream materials, including the following:

CR-39 resin: The most commonly used plastic lens material, lightweight, non fragile, with good optical properties, suitable for daily use. ‌

High refractive index resin: With a refractive index between 1.60 and 1.74 (such as 1.67 and 1.74), it can make the lens thinner and lighter, especially suitable for people with high myopia. ‌

Polycarbonate (PC) lens blank: also known as "space film", with strong impact resistance, light weight, and built-in UV protection function, suitable for children, athletes, or high-risk environments, but a low Abbe number may slightly affect visual clarity. ‌

Trivex lens blank: a high-performance resin that combines lightweight, impact resistance, and excellent optical properties, commonly used in sports glasses. ‌

Other less common materials include:

Crystal lens blank: Natural or artificial crystal with high hardness and high temperature resistance, but high cost and fragility, and is now less commonly used. ‌

Nylon lens blank: good elasticity, high temperature resistance, mostly used for sports goggles, but its optical performance is slightly inferior to resin. ‌