In the digital age, blue light exposure is becoming more frequent than it was in the past. People in the U.S. are being overexposed to blue light due to their use of electronic gadgets including computer screens, smartphones, and tablets. According to The Vision Council, 93.3% of the adult population spends more than two hours a day using or looking at a digital device. 60.8% of adults spend five or more hours on a digital device each day. For these reasons, Eye.D. Eyewear in Durango, CO takes a deeper look at blue light exposure, its effects, and what you can do to help combat these effects.
What is Blue Light?
Blue light is the highest energy light visible to the human eye and is naturally present in sunlight. The human body has grown accustomed to blue light. As such, our bodies are designed to react certain ways to this light. We interpret it as a signal to be alert, awake, and active. Furthermore, blue light impacts our moods, affects cognitive function, and helps with memory. The lack of exposure to a lower frequency blue light, such as the sky, has been attributed to depression and other mood disorders.
Humans have begun, however, to expose themselves to high amounts of HEV (high frequency) blue light artificially. The mediums in which humans are taking in more blue light include compact fluorescent light bulbs, LED televisions and light bulbs, computers, smart phones, e-readers, and tablets. The impacts of use of computers and devices is more of a concern than overhead lighting and televisions because they are so much closer to the eye.
Effects of Overexposure
The overexposure to blue light is a relatively new phenomenon, but eye doctors are already seeing the negative effects it can have on humans. The most common impacts include diminishing visual performance, increasing the risk of age-related macular degeneration (AMD), and disruption of the sleep cycle. We note a special concern for the age that children are beginning to be over exposed.
The short wavelengths associated with blue light behave differently than other wavelengths. When we take in natural blue light from the sun, we are absorbing it differently. This is because the fast-moving particles in the wavelength collide with air molecules and other particles and scatter. The scattering of these particles when the natural blue light hits the atmosphere is what creates the blue sky that we see.
This scattering of the fast-moving particles acts the same when blue light enters our eyes. However, our eyes do not focus blue light on the same plane as it does other types of light. This, in turn, can cause a slight distortion in how we perceive things. The eye’s fovea, the center of the retina, doesn’t have receptors that are sensitive to processing blue light. For this reason, blue light doesn’t actually contribute to our central detail vision. Instead, blue light blurs images and induces glare to the human eye. However, our eyes have evolved to continue to attempt to process the light information as we receive it. This normally isn’t a problem for the human eye, but with the increase of exposure to blue light it can cause fatigue and eyestrain.
Another common consequence related to over exposure of blue light is Age-Related Macular Degeneration (AMD). AMD is a common eye condition and the leading cause of blindness in people 50 and older. Though there are other contributing factors to AMD, a 2008 study completed by the Paris Vision Institute found that high-energy wavelengths are the most harmful to the retina. The blue light’s high-energy wavelengths actually cause retinal cell death. Constant exposure to this light can contribute to AMD.
The final, and more commonly known, consequence related to the exposure of blue light is our body’s physiological reaction to it. Blue light naturally triggers our bodies to suppress melatonin production in the brain since the sun naturally produces it. All forms of light actually trigger this response in the brain, but our bodies’ suppression of melatonin to blue light is significantly more powerful than with other forms of light. This suppression of melatonin can disrupt our sleep cycles. Studies show that by exposing ourselves to blue light a couple of hours before bed can actually delay deep REM cycles, which affects the sleep cycle overall. Poor sleeping habits can contribute to an array of health conditions including mood disorders and high blood pressure.
Natural Protection from Blue Light
Humans evolved to naturally protect themselves from blue light. This protection is called ocular lens pigment (OLP). This OLP is a substance in the eye that filters and protects vision from the effects of high-energy light. Over time we naturally accumulate OLP. We are born without this natural protection and it accumulates very slowly as we age. The youngest and those who have had cataract surgery, where the crystalline lens with the OLP has been removed, are especially vulnerable to both macular damage and eye fatigue. Now there are protections from blue light other than our bodies’ naturally occurring defensives.
The original attempt to combat these harmful high-energy wavelengths was by creating eyeglass lenses known as “Blue Blockers”. These eyeglass lenses claim to block 100% of blue light and UV lights. Though this may sound like a solution to the blue light problem, we still require a certain amount of blue light to see properly. By blocking out100% you risk color distortion and impaired vision.
There is a selection of blue light deflective coatings available on the market. These are often coupled with anti-reflective coatings and deflect roughly 20% of blue light. These deflect the blue light by directing part of the light spectrum away from the eye, hence the name deflective coating. They are most effective when combined with a lens with OLP filter.
Ocular Lens Pigment
In 2012 Ocular lens pigment (OLP) were introduced to the market. OLPs offer a wide range of selections, from progressive to traditional bi-focal designs. Manufacturers combat the exposure to blue and UV lights by infusing the lens monomer with a ratio of ocular lens pigment and melanin. This allows the OLPs’ lenses to mirror the natural light curve that is found in our eyes, which in turn filtersour the maximum amount of high-energy visible light at the shortest blue light wavelength and gradually allows more through as the wavelength approaches.OLP lenses are available for indoor use and also are available in sunglasses to help protect from AMD as well as enhancing visual acuity and reducing eye strain.
The long-term consequences of overexposure to blue light are disconcerting, to say the least. Unfortunately, we are becoming more reliant on our digital devices, which means that this exposure isn’t likely to decrease. For children not wearing glasses, you can limit use of computers and devices and you may be able to purchase blue light filters for them. To help protect your vision it may be worth considering investing in a pair of ocular pigment lenses to combat these effects. Eye.D. Eyewear in Durango, CO has a wide selection of glasses to help reduce the amount of blue light exposure you experience. Swing by today to speak to a knowledgeable staff member more about the long-term implications of blue light and to find a pair of glasses that will suit your needs.
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