Ocushield Anti blue light screen protector for laptops, monitors and PCs - Size 21-inch (16:10)  Ocushield screen protectors have been developed by qualified optometrists to filter blue and has an anti-glare coating to prevent eyestrain. Effectivity it blocks up to 90% of harmful light emissions reducing the chance of headaches and dizziness from a prolonged exposure to blue light. Reason to buy Ocushield – Anti blue light screen protector Accredited Class 1 Medical Device Improve sleep and protect your eyes with our blue light filter No retro orange tinge, a crystal-clear picture Infused privacy filter, stop prying eyes Anti-glare coating, no more reflections Anti-bacterial coating, good for shared devices Researched & developed by Optometrists in the UK