High energy visible (HEV) blue light, especially from electronic devices and LED lights, has been all over the news lately, primarily warning about sleep interference.
Curiously, the media is not shedding much light on another serious blue light hazard —especially for those with aging eyes.
Few people stop to think about light, much less the effects different colors of light can have on our bodies, moods, and overall health. Stepping outdoors into the sunlight, switching a light on indoors and the light shining from the screens of our televisions, computers and cell phones . . . light is all around us!
All of these things result in your eyes being exposed to a variety of visible and sometimes invisible light rays that can have a range of biological effects. The health effects of visible light, blue light as well as invisible ultraviolet (UV) and near-infrared radiation (NIR) have not been clearly elucidated until now.
We are perfectly adapted to the natural radiation of our sun on Earth by evolution. This becomes obvious when you look at the medical studies on light use prior to the advent of antibiotics. Original data clearly shows the health benefits of heliotherapy (solar radiation therapy) that living things get naturally.
Balanced, full-spectrum sunlight, which includes ultra violet and infrared light, is critical for optimum health and well-being. — Indoor, artificial lighting does not include these essential invisible light wavelengths..
Early on, the lighting manufacturers did not include invisible UV or NIR light. Presumably, their focus was limited to the ‘visual effects’ of light and not the ‘biological effects’ that research is discovering today. Apparently, the manufacturer’s never thought to test how this unnatural version of light would affect living things.
We have no natural defense to chronic blue light when near-infrared light is subtracted.
Sunlight includes an abundance of NIR light as well as visible red light. These longer wavelengths provide metabolic power to the cells and counterbalance the shorter blue light wavelengths.
HEV light is a very powerful stimulus and this helps explain why the eye must have near-infrared light present anytime blue light is present to offset the mitochondrial damage it can cause. Today’s artificial light is created without any stimulus of UV or NIR as is present in the sun..
The Good News
It’s well documented that some HEV blue light exposure is essential for good health and can make us feel better and increase our energy. Sunlight is the main source of blue light. Being outdoors during daylight is where many of us get most of our natural exposure to it. In its balanced form, blue light from the sun helps our bodies determine day from night, and thus, when it’s time for sleep. Blue light exposure during daytime hours helps maintain a healthful circadian rhythm that controls appetite, energy, mood, sleep, libido, and other body-mind functions. .
Additionally, research has shown that blue light boosts alertness, helps memory and cognitive function, and elevates mood. In fact, ‘blue light therapy’ is now used to treat the seasonal affective disorder (SAD) — a type of depression that’s related to changes in seasons that can result in debilitating fatigue, appetite changes, and mood disorders..
The Bad News
In addition to natural sunlight, there are many man-made, indoor sources of blue light which include fluorescent and energy-efficient LED lighting. Most notably, LED light bulbs, computer display screens, electronic notebooks, and smartphones emit significant amounts of HEV light. The amount of blue light that these devices emit is only a fraction of that emitted by the sun. However, the number of time people spend indoors radiated by unbalanced, energy-efficient light or using these devices within close proximity to the user’s face, have many health care professionals concerned about possible long-term effects of blue light —especially on eye health.
Risk of Macular Degeneration
The fact that blue light penetrates all the way to the retina of the eye is important because research has shown that too much exposure to blue light, especially from LED lights, can damage light-sensitive cells in the retina.
Invisible near-infrared light (NIR) helps prime the cells in your retina for ‘repair and regeneration’ and helps reduce the risk of macular degeneration.
In summation — be mindful that daily LED light exposure and/or staring at your television, computer, tablet, or phone before you go to bed is having a negative impact on your eye health and a good night’s rest.