Per the Occupational Safety & Health Administration: The preferred viewing distance for VDTs ranges between 18 and 24 inches (45.72 and 60.96 centimeters, respectively). FEATURES AND BENEFITS Filters 100% of the most damaging low-level blue and nearly 40% high energy visible light from tablets, phones, TV, computers and more. Our lenses code is BB40 for the Eyekepper violet block glasses. Anti fatigue Anti jet lag blue blocker Get maximum protection with ourpatented, multi layer coating designed specifically to reduce glare, reflect blue light away from the user and relieve long term eye strain caused by excess electronic device use. Whether you are looking for computer glasses for the office or a late night Netflix binge. Eyekepper glasses will give you the premium protection you are looking for If you are unfamiliar with blue light it's right next to UV light on the spectrum of light. It is comprised of very high energy and a low wavelength very similarly to UV light. All of our electronic devices with a back-lit screen give off large quantities of blue light (Iphones, Ipod, Laptop, Computer TV.) This blue light messes with our internal clock making us think it's mid day when really it can be closer to night and stops our body from naturally producing the melanin that helps us fall asleep late at night CARE To avoid damage, never clean your computer glasses with paper towels or clothing or alcohol, and also avoid using household detergents or soaps. While a few mild soaps don't harm lenses, today's extra strength soaps are powerful enough to slowly disintegrate lens coatings.

?NO RISK TO TRY - blue light blocking reading glasses In case any broken problem happens, please do not hesitate to contact Eyekepper customer service to solve the problem until you are satisfied. ?4 PACK READERS FOR MEN - The blue light blocking specs you can keep a pair in the bedroom, a pair in the living room, and a pair in the office. You don't need to run around looking for glasses when you want to read. ?METAL FRAME AND CLEAR LENSES - These blue light filter reading glasses is made of quality metal. The lens are crystal clear. ?RIMLESS DESIGN - Lightweight rimless cut blue rays readers for durable and comfortable long-wearing. Elegant design can make you look more professional and stylish at work or in life. ?FRAME HEIGHT - Men's blue light blocking reading glasses with spring hinges. Frame height about 1.14 inches (29mm).