Case Study

Protecting the Eyes from Blue Light

Manufacturer wanted to fulfil demand for highly-transparent polycarbonate lenses.

Eyeglass lens manufacture Product development

The manufacturer featured in this case study designs, develops, and manufactures eyeglass lenses. Recent years have seen increased attention paid to ways that lenses can help keep the eyes healthy.
Although eyeglass lenses with ultraviolet ray protection are already on the market, the living environment has changed in recent years with the prolonged use of personal computers and smart-phones, and it is desired to develop eyeglass lenses that are even more eye-friendly and block out high-energy visible light (bule light) , which is said to be particularly harmful to the eyes among visible light rays.


Light and Strong Polycarbonate Resin is Popular Choice for Eyeglass Lenses but Also Presents Challenges

There are two main approaches to obtaining blue light block properties with eyeglass lenses made by polycarbonate. One is to coat the lens surface with layer blocking blue light, and the other is to give the resin itself the ability to block blue light. However, both approaches present tricky problems.

In some cases, the coating method is concerned about lens coloration , and the coating must be changed from a single layer to multiple layers, which affects the complexity of the manufacturing process and production time. The manufacturer is also required to achieve accurate wavelength suppression, which in some cases means installing new equipment. Meanwhile, because the approach of imbuing the polycarbonate resin with blue light block properties require the application of new wavelength suppression technology in addition to conventional manufacturing techniques, the manufacturer was unsure whether such an approach would actually work.

Under the circumstances, eyeglass users have been waiting for the resin for eyeglass lenses that has highly transparent and effectivity blue light block property.

Summary of the Problem
  • The manufacturer wanted to create a transparent and blue-light block eyeglass lens.
  • The manufacturer wanted to ensure that its manufacturing process would be flexible while also improving productivity (by keeping the process simple).