Because they are shorter, Artificial Electronic Blue Light Waves or High Energy Visible (HEV) wavelengths flicker more easily than longer, weaker wavelengths. This type of flickering creates a glare that can reduce visual contrast and affect sharpness and clarity. This flickering and glaring may be one of the reasons for eyestrain, headaches, along with physical and mental fatigue caused by many hours sitting in front of a computer screen or other electronic device. Natural filters in the human eye do not provide sufficient protection against blue wave light rays from the sun, let alone the blue light emanating from these devices and from fluorescent-light tubes. Prolonged exposure to blue light may cause retinal damage and contribute to age-related macular degeneration, which can lead to loss of vision over time.