The human eyes are sensitive to a narrow band of light wavelengths that range from blue (short wavelength and high energy) to red (long wavelength and lower energy). Blue light makes up approximately one third of the visible spectrum. The sun is our main and natural source of blue light. However, with advances in technology, we are also being exposed to other sources of blue light such as computer monitors, smartphone screens, flat screen televisions and LED lights.
While these sources generate blue light at much lower intensity than the sun, we are exposing ourselves to them for longer periods of time and at much closer distances. This can cause eye strain because blue light scatters more in the eye and is not focused as easily as lower energy wavelength light. This scatter creates “visual noise” that reduces contrast and can contribute to digital eye strain.
Natural blue light from the sun is important for maintaining the circadian rhythm (our natural sleep/wake cycle). It also helps to boost mood, memory and cognitive function. Exposure to too much artificial blue light, especially at night, from electronic devices may lead to poor sleep quality, difficulty falling asleep, and daytime fatigue because it has been shown to suppress melatonin production, sleepiness and morning alertness This is especially problematic for adolescents, who prefer sleep/wake cycles that are considerably delayed compared to younger children or adults.
Extended exposure to blue light over a lifetime, particularly from the sun, is likely to cause harm to the eye. It leads to conditions such as cataracts (clouding of the lens of the eye resulting in decreased vision) and signs resembling macular degeneration (a deterioration of the central part of the retina, which is essential for reading, driving and recognizing colours and faces). Studies have shown that it is the cumulative exposure to blue and ultraviolet light that causes these effects. Children are more vulnerable to the effects of ultraviolet and blue light because their eye lenses are less able to filter out high energy blue light
Evidence suggests that exposure to blue light in the 470-490nm wavelength range (lower energy) is less damaging to the eye than blue light in the 400-470nm wavelength range (higher energy) and essential for maintaining a healthy circadian rhythm. Development of LEDs with a peak emission in the safer range may represent an important advancement for ocular health.
While there is no clinical evidence of a damaging effect of exposure to artificial high energy blue light, children’s exposure to artificial light from electronic devices should be monitored and controlled. Over time, there might be accumulated damage to the eye from blue light exposure.
A healthy diet, rich in leafy green vegetables and colourful fruits, is important for general good health as well as for vision health. A healthy diet provides the vitamins and minerals that are essential for vision health and contribute to the eyes’ own natural defenses against the effects of blue light.
Good sleep is also essential for attention, learning, mood, and general well-being. The effects of blue light on the sleep cycle may be minimized by avoiding bright screens for two to three hours before bedtime and seeking outdoor light exposure earlier in the day.
Do I need blue-blocking lenses?
Research has demonstrated that extended exposure to sunlight is damaging to the eye. Therefore, it is good practice to protect the eyes from the sun, including wearing UV-blocking sunglasses. There is no clinical evidence that artificial blue light at low intensity and shorter exposure periods is harmful to the eye. Research suggesting a damaging effect of blue light on eye cells has only been conducted in vitro (in the lab) rather than on the living human eye.
There are filters and apps that reduce blue light from screens without affecting visibility and special glare-reducing lens coatings that block high-energy visible blue light. Whether or not to add blue-blocking coating on your prescription lenses is an individual decision that should be made with an optometrist, who as a primary eye care provider, is your best resource for making an informed decision. Together you can discuss your individual risk factors such as age, risk and length of exposure, history of or current eye conditions, and general eye health.
In an increasingly digital world, we are exposed to artificial lighting more than ever before. Artificial lighting not only causes issues such as eye strain, headaches and blurred vision, but also impacts one of our most important internal biological processes: sleep.
Our sleep cycle is regulated by our internal body clock or circadian rhythm, which uses the light sensors in our eyes to track what our body perceives as daylight in order to match our schedule to our environment.
This process can be disrupted when exposed to artificial light, which contains blue light. Blue light is used by LED screens including televisions, computers and our phones, and can be problematic as it closely mimics natural sunlight. Because of this, our body interprets blue light as sunlight and sends signals to the brain that we should be awake. This can throw off our circadian rhythm and contribute to insomnia and other sleep-related issues.
Fortunately, there are steps you can take to help alleviate some of the issues caused by blue light to ensure a good night’s sleep:
Your eyes are your window to the world – they allow you do everything from performing everyday tasks to enjoying the most precious moments life has to offer. That’s why it’s important to be proactive and make vision a priority. Check out these simple tips to keep your eyes healthy:
It was only a matter of time until an eye syndrome would develop that’s directly related to the modern human habit of staring relentlessly at computer and device screens for hours on end. This contemporary eye syndrome affects those who focus on screens all day as part of their jobs or studies. It also impacts the eyesight and eye comfort of those who look at their phones for hours on end.
Regardless of the cause, digital eye strain (DES) is a very real phenomenon that’s been reported by 31% of adults and over twice as many millennials. The condition is also called “computer vision syndrome,” and it’s not fun.
Understand the Causes of DES
There isn’t one reason why your eyes may start to feel dry and itchy after staring at your computer all day. There isn’t one easy-to-pinpoint reason why your eyesight gets blurry after scrolling through social media on your tablet all evening. The truth is, there are multiple reasons why your device usage is impacting your vision and eye comfort.
Once a proper eye exam rules out problems like glaucoma, myopia, and astigmatism, you must address vision-impacting issues in your workspace. Are you sitting too close to the screen? Experts advise being at least an arm’s length away.
You may need to view text in a larger font or adjust the height of your desk, chair, or computer screen. What’s the angle at which you view your device? Aim for a downward angle from your eyes to your device, usually an angle of about 15 or 20 degrees. Sit up straight, making sure you aren’t having to slouch or stretch to see your monitor.
Stock Up on Items to Reduce DES
Special glasses definitely help, but you may need to invest in some other helpful items to reduce the likelihood or impact of DES. Since excessive glare is one cause of computer vision syndrome, reduce the glare in your environment with room-blocking curtains.
If a lamp is the source of glare, purchase a darker lampshade or move the lamp to a spot where it doesn’t beam onto your screen. Purchase monitor- and device-friendly wipes to keep screens free of smudges and debris.
Next time you’re at the pharmacy, grab some gel-filled eye masks you put in the fridge for a cooling eye refresher. Ask your optometrist to recommend eye drops that help keep your eyes moist. If you have allergies, take steps to reduce pollen in your environment, and remember to take your antihistamine as prescribed.
Wear Your Computer Glasses
You can purchase specialty computer glasses or have your eye doctor create a custom pair of glasses for you. These glasses have features such as anti-glare lenses and lenses that filter out the blue light emitted by devices.
Many computer glasses are tinted yellow. This helps increase the contrast between letters and backgrounds on device screens. There are also progressive lenses available that let you go from looking at a computer to reading a book or viewing something in the distance easily.
But the glasses won’t work if you don’t wear them. If possible, leave one pair of computer glasses at home and one pair at work so you always have some at hand.
Compromise to Save Your Eyes
Set limits on yourself when using your PC or devices. Go beyond the 20-20-20 rule, which is the advice to take 20 seconds to look at something 20 feet away every 20 minutes. Give your eyes routine breaks from devices altogether.
Get out in nature without your phone, or go for a walk without your tablet, and let your eyes take in all of the world around you. By letting your eyes enjoy periodic vacations from the little screens in your life, you exercise your eye muscles. They grow stronger when you look at clouds, skyscrapers, and faraway mountains.
Remember to blink when looking at your devices too. Because of the way people read text on computers, they tend to blink their eyes far less often. This is one of the reasons your eyes may dry out and grow itchy after looking at your phone or laptop for a long time. By blinking, you refresh your eyes with natural lubricant.
In most cases, DES resolves itself once you take a rest period away from screens. Computer glasses often help when you must stare at a device for long periods. If your problem is due to another underlying eye problem, specialty treatment or glasses for that problem may resolve the DES too.
Vision therapy is sometimes prescribed for people who have difficulty with focus and depth perception. A simple pair of glasses is not enough to fix these problems or problems related to weakness or degeneration of eye muscles.
UV rays aren't the only type of harmful rays. Blue-violet light can also damage your eyes and it's everywhere!
Sunlight is made up of red, orange, yellow, green, blue, indigo and violet light. When combined, it becomes the white light we see. Each of these has a different energy and wavelength. Rays on the red end have longer wavelengths and less energy. On the other end, blue rays have shorter wave lengths and more energy. Blue light reaches deeper into the eye and its cumulative effective can cause damage to the retina.
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.
Blue light exposure you receive from screens is small compared to the amount of exposure from the sun. And yet, there is concern over the long-term effects of screen exposure because of the close proximity of the screens and the length of time spent looking at them. Many believe children’s eyes absorb more blue light than adults from digital device screens.
So what can you do to protect your family?
If you can't limit the amount of screen time you are exposed to, ask about Crizal Prevencia, it is a blue light filter coating that helps ensure the long-term health of your eyes. This can be added to any prescription eye glasses purchased at insight eyeworks.
With over 30 years experience licensed optician Joe Bushara and his highly experienced team, bring you the latest trends in frames and technologies in lenses from around the world.