BLUE BLOCKING GLASSES - protect your eyes from harmful artificial light emitted from electronic devices such as smart phones and computers. Our on-trend blue filter glasses are suitable for both men and women a practical yet stylish fashion accessory that also work at giving you optimum protection from artificial, fluorescent and LED light exposure SIZE INFORMATION - lightweight, weighing just 20g our blue blockers are designed with comfort in mind. Suitable for a range of face sizes and shapes the acetate frames measure 140mm long with the CR39 lenses 53mm wide and 44mm high. The nasal spacing is a comfortable 19mm and the temple length a generous 136mm PREPARE FOR A GOOD NIGHTS SLEEP WITH BLUE BLOCKER LENSES - Exposure to too much blue before bed can have a serious effect on your circadian rhythms by slowing or stopping the production of melatonin (the chemical in your brain that tells your body it's time to go to bed). Avoid the negative side-effects of late-night blue light exposure by wearing our blue light blocking lenses