UV420  is a blue light that comes from artificial elements such as LCD Monitors, Smartphones and Tablets. UV light and other forms of high-energy light come not just from sunny skies, they also come at us from cloudy or rainy skies, and even in reflected light.

Short-term exposure to UV rays can cause photo-keratitis, which is sunburn of the eye. Over a long period, it can lead to cataracts. As for the light we can see, it is made up in part of high-energy visible light (HEV light), which is known to potentially cause Age-related Macular Degeneration (AMD) as we get older.