--Blue Light Explained-- Visible everywhere in our life Wavelengths of blue light are between 380nm to 495nm in the range of visible lights with strong energy. It's widely discovered in led light sourced products such as pc, cell phone, game machines and TV etc. Caused Digital Eye Fatigue Short wavelength, high energy blue light scatters more easily than other visible light and makes it not as easily focused. When you're looking at your digital screen that emit significant amounts of blue light, this unfocused visual light reduces contrast and can contribute to digital eye strain. Sleep Disruption Blue light is very important in regulating circadian rhythm Blue light can penetrate the crystalline to reach the retina, too much exposure to blue light can damage light-sensitive cells in the retina, which can lead to permanent vision loss. Also, the strong energy can deepen facial oxidation and form chloasma Disrupt Your Body’s Natural Cycle It is so important in regulating our body's natural sleep and wake cycle in order to get a good sleep, but absorb too much blue light can disrupt this cycle, causes you cannot to fall asleep at night and cannot wake up normally at the next morning --6 Layer Protection Screen Filter-- 1.Anti-static screen protector 2. Anti-scratch screen protector 3. Blue light blocking screen protector 4. UV400 protection screen protector 5. Radiation Protection screen protector 6. Relieve the fatigue of eyes screen protector --MUYBUY Lifetime Replacement Warrant-- We will send you replacements free of charge for: -Installation problem such as bubbles or other user error -Damaged screen protectors -Does not fit your device