High-energy visible (HEV) light has become one of the hottest trending topics in eye care in the past few years. There are at least three reasons for this growing interest in HEV, or “blue” light:
1. Though HEV light has less energy than ultraviolet (UV) radiation, HEV rays aren’t filtered by the Earth’s ozone layer or the cornea and lens of the human eye like UV rays are. Instead, they penetrate deep into the eye, all the way to the retina. Risks to the retina that once were believed to be associated with UV exposure may in fact be caused by cumulative exposure to HEV light instead — or a combination of UV and HEV rays.
2. The use of notebook computers, tablets, smart phones and other portable electronic devices has exploded in the past twenty years. The potential eye health implications of this trend are not fully understood, and since these devices emit blue light, many eye care providers are concerned.
3. Incandescent light bulbs for residential use are being phased out and replaced by light-emitting diode (LED) bulbs, which use up to 85 percent less energy and can last up to 20 years longer than incandescent light sources. But LED bulbs emit significantly more HEV light than incandescent light bulbs, which also is fueling concern about potential eye health concerns from blue light exposure.
As its name describes, high-energy visible (HEV) light is electromagnetic radiation that is both “high-energy” (and thereby has potential to cause harmful changes in living tissues) and is visible.