I have used this a few times. Please check the condition of the product in the photos before purchasing. The following is a quote from the official website: It is said that 1 in 3 people have sleep-related problems. Getting good quality sleep helps to regulate your body's condition. SLEEPING cuts approximately 70% of blue light, compared to the approximately 40% cut of blue light by a standard SCREEN lens. By blocking artificial light such as LED light, which interferes with the secretion of melatonin, also known as the sleep hormone, it promotes natural sleep and supports comfortable sleep onset. By using it every day, the time it takes to fall asleep is shortened, leading to better quality sleep. By using it 2 hours before bedtime for 15 days, you can return to your natural circadian rhythm and restore your own cycle (according to Opinionway). An iconic, classic frame that doesn't follow trends. The rounded frame gives a gentle impression and softens the impression of the face. < Features > ・Cuts blue and purple light emitted from lights, screens, and LEDs. ・By blocking artificial light such as LED light, it does not interfere with the secretion of melatonin and promotes natural sleep. ・We recommend wearing the sleeping glasses 2 hours before bedtime for the first 15 days. < Notes > ・The model shooting images may appear different from the actual color depending on the lighting and the viewing environment of your computer, etc. Please refer to the detailed images taken of the product itself for the product's color. SIZE SPEC Material: Frame/Plastic, Lens/Plastic Visible light transmittance: 77.7% Ultraviolet transmittance: 0.1% or less Country of origin: Taiwan