What is Blue Light?
Blue light is a colour in the “visible light spectrum” that can be seen by the human eye. It has a very short wavelength and so produces a higher amount of energy. Studies suggest that, over time, exposure to the blue end of the light spectrum could cause serious long-term damage to your eyes. We all know how important it is to protect our eyes from the sun’s harmful rays; but what about the harmful effects of blue light rays?
Sources of blue light include the sun, digital screens (TVs, computers, laptops, smartphones, and tablets), electronic devices, fluorescent, and LED lighting. So blue light really is everywhere. When outside, light from the sun travels through the atmosphere, the shorter, high energy blue wavelengths collide with the air molecules causing blue light to scatter everywhere, this is what makes the sky look blue. In its natural form, your body uses blue light from the sun to regulate your natural sleep and wake cycles: your circadian rhythm. Blue light also helps boost alertness, heighten reaction times, elevate moods, and increase the feeling of well being. The artificial sources of blue light are where our larger problems lie.
Why should we be concerned about blue light exposure?
The evolution in digital screen technology has advanced dramatically over the years, and many of today’s electronic devices use LED back-light technology to help enhance screen brightness and clarity, these LEDs emit very strong blue light waves. Because of their wide-spread use and increasing popularity, we are gradually being exposed to more and more sources of blue light and for longer periods of time. Because blue light waves are among the shortest, highest-energy wavelengths in the visible light spectrum the wavelengths flicker more easily than longer, weaker wavelengths. This kind of flickering creates a glare that can reduce visual contrast and affect sharpness and clarity. This flickering and glaring may be one of the reasons for eyestrain, headaches, physical, and mental fatigue caused by many hours sitting in front of a computer screen or other electronic device.
Our eyes’ natural filters do not provide sufficient protection against blue light rays from the sun, let alone the blue light emanating from these devices or from blue light emitted from fluorescent-light tubes. Prolonged exposure to blue light may cause retinal damage and contribute to age-related macular degeneration, which can lead to loss of vision. Yes, blue light can help elevate your mood and boost awareness, but chronic exposure to blue light at night can lower the production of melatonin, the hormone that regulates sleep, and disrupt your circadian rhythm. Harvard researchers have linked working the night shift and exposure to blue light at night to several types of cancer (breast, prostate) diabetes, heart disease, obesity and an increased risk for depression. Researchers aren’t exactly sure why exposure to blue light at night seems to have such detrimental effects on our health, but it is known that exposure to light suppresses the secretion of melatonin and lower melatonin levels might explain the association with these types of health problems.
Blue light and Digital Eyestrain
Most of us spend the majority of our waking hours staring at a digital screen, whether it’s the computer at work, our personal cell phone, playing a video game, or just relaxing and watching TV. Digital eyestrain is a new term used to describe the conditions resulting from the use of today’s popular electronic gadgets. Digital eyestrain is a medical issue with serious symptoms that can affect learning and work productivity. Symptoms of digital eyestrain, or computer vision syndrome, include blurry vision, difficulty focusing, dry and irritated eyes, headaches, neck and back pain. Learn more here -> www.eyeqjamaica.com/protection-from-des
Digital eyestrain has overtaken carpal-tunnel syndrome as the number one computer-related complaint and digital eyestrain does not just affect adults, children are also at risk for eyestrain due to their growing use of digital devices. Children today have more digital tools at their disposal than ever before – tablets, smartphones, e-readers, videogames are just among a few. And studies estimate that children and teenagers (ages 8-18) spend more than 7 hours a day consuming electronic media. Before age 10, children’s eyes are not fully developed. The crystalline lens and cornea are still largely transparent and overexposed to light, so too much exposure to blue light is not a good thing. Parents should supervise and limit the amount of screen time their children are permitted and ensure they add protective measures, like blue control eyewear.
Blue light and Macular Degeneration
There’s growing medical evidence that blue light exposure may cause permanent eye damage; contribute to the destruction of the cells in the center of the retina; and play a role in causing age-related macular degeneration, which can lead to vision loss. Melanin is the substance in the skin, hair, and eyes that absorbs harmful UV and blue light rays. It’s the body’s natural sunscreen protection. Higher amounts of melanin afford greater protection, but as we age we lose melanin, so that by age 65 half of the protection is gone making us more susceptible to eye disease such as macular degeneration. The retina is a very thin, multi-layered tissue covering the inner eyeball. The retina can be harmed by high-energy visible radiation of blue/violet light that penetrates the macular pigment found in the eye. A low macular pigment density may represent a risk factor for age-related macular degeneration by permitting greater blue light damage to the retina. A Harvard medical study states that “High Energy Visible (HEV) blue light has been identified for years as the most dangerous light for the retina. After chronic exposure, one can expect to see long-range growth in the number of macular degenerations, glaucomas, and retinal degenerative diseases”. And a paper published by the American Macular Degeneration Foundation (AMDF) reports that “the blue rays of the spectrum seem to accelerate age-related macular degeneration (AMD) more than any other rays in the spectrum”.
Key points to remember:
- Blue light is everywhere. Sunlight is the main source of blue light, and being outdoors during daylight is where most of us get most of our exposure to it. But there are also many man-made, indoor sources of blue light, including fluorescent and LED lighting, and flat-screen televisions. Most notably, the display screens of computers, smartphones, and other digital devices emit significant amounts of blue light. The amount of HEV light these devices emit is only a fraction of that emitted by the sun, but the amount of time people spend using these devices and the proximity of these screens to the user’s face have many eye doctors and other health care professionals concerned about possible long-term effects of blue light on eye health.
- The eye is NOT very good at blocking blue light. Anterior structures of the adult human eye (the cornea and lens) are very effective at blocking UV rays from reaching the light-sensitive retina at the back of the eyeball. In fact, less than one percent of UV radiation from the sun reaches the retina, even if you aren’t wearing sunglasses. (Keep in mind, though, that sunglasses that block 100 percent of UV are essential to protect these and other parts of the eye from damage that could lead to cataracts, snow blindness, a pinguecula and/or pterygium, and even cancer.) On the other hand, virtually all visible blue light passes through the cornea and lens and reaches the retina.
- Blue light exposure may increase the risk of macular degeneration. The fact that blue light penetrates all the way to the retina (the inner lining of the back of the eye) is important, because too much exposure to blue light can damage light-sensitive cells in the retina. This causes changes that resemble those of macular degeneration, which can lead to permanent vision loss. Although more research is needed to determine how much natural and man-made blue light is “too much blue light” for the retina, many eye care providers are concerned that the added blue light exposure from computer screens, smartphones, and other digital devices might increase a person’s risk of macular degeneration later in life.
- Blue light contributes to digital eye strain. Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused. When you’re looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual “noise” reduces contrast and can contribute to digital eye strain. Research has shown that lenses that block blue light with wavelengths less than 450 nm (blue-violet light) increase contrast significantly. Therefore, eyewear with blue control lenses may increase comfort when you’re viewing digital devices for extended periods of time.
- Blue light protection may be even more important after cataract surgery. If you have cataracts and are about to have cataract surgery, ask your surgeon what type of intraocular lens (IOL) will be used to replace your cloudy natural lens, and how much blue light protection the IOL provides. After cataract surgery you might benefit from eyeglasses that have lenses with a special blue light filter — especially if you spend long hours in front of a computer screen or using other digital devices.
- Not all blue light is bad. So, is all blue light bad for you? Why not block all blue light, all the time? Bad idea. As mentioned, it’s well documented that some blue light exposure is essential for good health. Research has shown that high-energy visible light boosts alertness, helps memory, and cognitive function and elevates mood. In fact, something called light therapy is used to treat seasonal affective disorder (SAD) — a type of depression that’s related to changes in seasons, with symptoms usually beginning in the fall and continuing through winter. The light sources for this therapy emit a bright white light that contains a significant amount of HEV blue light rays. Also, blue light is very important in regulating circadian rhythm — the body’s natural wakefulness and sleep cycle. Exposure to blue light during daytime hours helps maintain a healthy circadian rhythm. But too much blue light late at night (reading a novel on a tablet computer or e-reader at bedtime, for example) can disrupt this cycle, potentially causing sleepless nights and daytime fatigue.
So, how do we stay protected?
- The first step to protect your eyes against eye strain from blue light in devices is to take regular breaks using the “20-20-20” rule: Every 20 minutes, shift your eyes to look at an object at least 20 feet away for at least 20 seconds. You can also use artificial tears to refresh your eyes when they feel dry.
- Also, keep computer monitors at minimum brightness needed to see screen comfortably and remember to BLINK as staring at screens we don’t blink enough. 🙂
- Next, use eyewear with Blue light filters. Blue light filters which can be incorporated in lenses reduce exposure to the blue light emitted from LED screens. These special-purpose glasses are available without an eyeglass prescription if you have no need for vision correction or if you routinely wear contact lenses to correct your eyesight. Or computer glasses can be specially prescribed to optimize your vision specifically for the distance from which you view your devices. If you have presbyopia and routinely wear progressive lenses or bifocals, prescription computer glasses with single vision lenses give you the additional benefit of a much larger field of view for seeing your entire computer screen clearly.
- You also may want to consider photochromic lenses, which provide seamless protection from UV and blue light both indoors and out and also automatically darken in response to UV rays outdoors to increase comfort and reduce glare. Once you come and visit us, we will be able to assess which vision correction and lens features best suit your needs for viewing your computer and other digital devices and protecting your eyes from blue light.
- Add reflection-free (anti-glare) coatings to lenses as these aid vision by reducing glare on the lenses, and anti-fatigue lenses like Hoya’s Sync range reduce eyestrain and have been developed specifically for screen use.
- Add “Blue light filters” to your electronic devices, there are several apps which can be used to do this and prevent significant amounts of blue light emitted from these devices from reaching your eyes without affecting the visibility of the display. Some are made with thin tempered glass that also protects your device’s screen from scratches. examples of blue light filters for digital devices include: Eyesafe (Health-E), iLLumiShield, RetinaShield (Tech Armor), Retina Armor (Tektide), Frabicon, and Cyxus.
We hope you have found these tips helpful! Who needs protection from blue light exposure?
We all do. Everyone needs to take precautions against the effects of blue light. Whether we work in an office or play in the sun; spend hours staring at a computer screen, or texting on our cell phones, we are all being exposed to blue light. If you have any queries please don’t hesitate to ask us via email or contact our offices.
To learn more about the measures we are taking to ensure your safety visit – https://www.eyeqjamaica.com/covid-19
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