Blue light-emitting diodes (LEDs) are semiconductor devices that are commonly used as light sources in LED-backlit liquid crystal displays of various electronic appliances such as smartphones, computer screens, and LED lamps. As compared with a normal lamp, the LED lamp has several advantages, such as less heat, longer life, and good energy efficiency. Blue LEDs also display several other properties apart from being a light source. Blue light has been reported to be lethal to insects.1 Additionally, blue LED light is shown to display a therapeutic effect in seasonal affective disorder.2 However, blue LED emits only short-wavelength high-energy visible light and long-time video display terminal works expose human eyes to blue LED light. Further, its night-time exposure can suppress the secretion of melatonin, resulting in sleep disorders.3–5 Moreover, exposure to blue LED light leads to increased production of reactive oxygen species (ROS).6 Oxidative stress induced by ROS is known to trigger photoreceptor cell7 and retinal pigment epithelium (RPE) cell death.8 Oxidative stress-induced RPE cell death may become a risk factor for age-related macular degeneration (AMD), which is the main cause of blindness in industrialized nations.9,10 Therefore, overexposure to blue light may be a risk for the progression of AMD.8,9 While wet AMD can be treated by several antiangiogenic drugs such as Ranibizumab,11 there is no effective treatment yet for dry AMD.