Updated: Aug 17, 2020
Glasses Lenses Material
At present, common lens materials are glass, PC, and resin.
The earliest glasses used for myopia are glass lenses, which have the advantages of high hardness, wear resistance, and high refractive index processing for high myopia patients.
The disadvantages are heavy, fragile, difficult to coat, and mostly spherical mirrors. Nowadays, glass lenses are rarely used. The high refractive index customized glass lenses provided by some companies are often targeted at customers with myopia of more than 1,000 degrees.
PC is a plastic material. It has the advantages of being light and easy to coat. It is also tough and not easily broken. The PC lens can be processed to a certain thickness to be used as bulletproof glass, space shuttle portholes, space suit masks, etc., so PC lenses are also called space Film, universe film. For myopia lenses, PC is widely used in lenses with a refractive index of 1.60.
But PC also has many shortcomings. For example, it is not wear-resistant and requires coating to increase the hardness of the lens; it is easy to be deformed by force and is not suitable for plastic and rimless frames; Abbe number is too low, and coating is needed to improve this problem.
The most commonly used lens material at present.
Wearability was once the biggest disadvantage of Hi-index lenses. Therefore, many brand manufacturers have hardened the surface of the lens in response to this shortcoming: the surface hardness of the original ordinary resin lens is 2-3H, after hardening treatment, the hardness reaches 4-5H, while the hardness of the current resin lens It has exceeded 6-7H. Adding a hard coating improves the lack of wear of the lens. With the continuous advancement of technology, it will get closer and closer to the surface hardness of the glass lens.
It has good elasticity. Due to the displacement space between organic molecular chains, the elasticity is 23-28 times that of glass sheets. Determines another major characteristic of the resin sheet-good impact resistance, so it is not easy to break, safe and durable
Machinability: Excellent, it is feasible to process full frame, half frame and frameless multi-type processing. Permeable dyeing can be used to dye the lens into a personal favorite color.
Thermal performance: Do not use in an environment above 60 degrees, otherwise the surface anti-reflective film will break, and even cause the anti-reflective film to fall off.