The old belief that too much of a good thing can be harmful is often vindicated by science. Sunshine is a good example of this. Exposure to UV radiation in sunlight promotes vitamin D production in the skin. This is healthy. On the other hand, too much UV exposure causes sunburn, skin cancer, and cumulative eye damage. While the health risks of too much UV are well documented, science is only now discovering the downside of excessive blue light exposure.
Why Blue Light Can Cause Eye Damage
Why is blue light a problem, and not some other color such as red? Blue light is at the edge of the visible light spectrum. Just beyond blue light lies ultraviolet, an invisible but highly energetic form of light. It is this high energy that damages the skin and the eye’s cornea and lens.
Because blue light is next to UV in the light spectrum, it too is energetic, though not to the same degree as UV. This energy means that blue light can also cause changes to the eye. But because blue light is weaker than UV, the damage takes longer to occur. In fact, it takes many decades of exposure for damage such as age related macular degeneration (AMD) to occur. As you go toward the other end of the visible light spectrum (the colors of the rainbow) to the color red, the light’s energy progressively weakens. Therefore, red lacks sufficient energy to damage cells.
UVB mostly damages the cornea because most of it is absorbed there, while UVA damages the eye’s lens, where most of it gets absorbed. This leaves the back of the eye, called the retina, touched by small amounts of UVA. However, blue light reaches the retina where it can exact its slow, long-term damage. This is why scientists believe blue light plays a role in AMD, along with small amounts of UVA. AMD is a slow degeneration of the center of the retina called the macula.
How Blue Light Affects Your Wake/Sleep Cycle
Blue light exposure to pigments in the eye affects your wake/sleep cycle, or circadian rhythm. When you’re outside during the day, or when sunlight fills your room, the blue light makes you wakeful and alert. When the sun sets, the absence of blue light triggers your sleep cycle, which gets you ready for a good night’s sleep.
This mechanism worked well until digital devices and energy-saving lighting, such as LEDs, became a part of everyone’s lives. This technology emits blue light and disrupts the sleep cycle when used late in the evening and night.
How Blue Light Reduces Visual Acuity
Different colors passing through a lens have slightly different focal lengths. However, the focal length of blue light deviates the most. Because the eye’s lens can’t accommodate the different color focal lengths at the same time, the image formed is less than crisp. This is especially true when blue light is present. Blue light also scatters within the eye, which further reduces visual acuity. This is why blue font on red or vice-versa produces eyestrain.
Nike Prescription Glasses Clear Blue Blocker Lens
Eye damage, sleep disruption, eyestrain, and reduced visual acuity are the potential consequences of blue light exposure. While you can use blue light screen protectors on some artificial blue light sources, you can’t screen all of it out. For one thing, there’s the matter of sunlight. Even the diffuse light that penetrates cloud cover contains blue light. If you can see the sky when standing in the shade on a sunny day, blue light is reaching your eyes.
In short, blue light is everywhere. It’s cost prohibitive, impractical, and ultimately impossible to apply screens to all blue light sources. The best solution is placing a blue light blocker over your eyes.
Nike prescription glasses with clear blue blocker lenses provide protection without the yellow or orange tints used in computer glasses. That means you can use them for all of your daily and nightly activities without distorting your color perception. Without blue light, contrast is enhanced. This is useful when driving in fog or thick haze, and when enjoying the view while walking and hiking. Finally, LED lighting in your home, and evening use of televisions, computers, and mobile devices won’t affect your sleep.
If you have any questions about using blue blocker lenses on your Nike prescription glasses, don’t hesitate to contact us.