Modern screen devices emit large amounts of blue light. Blue light, especially the one between 420-460 wavelengths, is a harmful high-energy light proven by medical researchers to cause eye disease. Using screen devices for an extended period of time can cause eyes fatigue and chronic inflammation. Using anti-blue light filters can reduce this health problem from happening.Approved by SGS, blocking out up to 49% of harmful blue light, relieving computer eyestrain. (380nm - 450nm)