Blue Light: What Is It And How Does It Affect Your Eyes?

What Is Blue Light?

Blue light, also known as high-energy visible (HEV) light, is a color in the visible light spectrum that can be seen by human eyes. These wavelengths of visible and non-visible light are measured in nanometers (nm), and, in general, the shorter the wavelength, the higher the energy. Blue light is a short wavelength, which means it produces higher amounts of energy.

Unlike other forms of light, the eyes cannot effectively filter blue light, so more can pass through the eye to the retina. Blue light produces both benefits and concerns for our eyes and overall health.

Where Are You Exposed To Blue Light?

The largest source of blue light is sunlight. In addition, there are many other sources:

  • Fluorescent light
  • Fluorescent light bulbs
  • LED light
  • Flat screen LED televisions
  • Computer monitors, smart phones, and tablet screens

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. According to an NEI-funded study, children’s eyes absorb more blue light than adults from digital device screens.

Benefits of Blue Light?

Moderate amounts of blue light are essential for good health.

  • Promotes alertness
  • Boosts memory and cognitive function
  • Elevates mood
  • Regulates circadian rhythm

Blue Light and Digital Eyestrain

Using digital devices up close or for long periods can lead to digital eyestrain.

Research has shown that when people use computers, laptops, and other digital devices, they tend to blink less often than normal. Fewer blinks can mean less moisture.

Digital eyestrain means different things to different people, but is generally related to the focusing system of the eyes.

When your eyes are strained from staring at a blue-light-emitting screen, you might notice:

  • dry eyes
  • sore or irritated eyes
  • tired eyes
  • headaches
  • facial muscles fatigued by squinting

Blue light scatters more easily than most other visible light. This may make it difficult for your eye to focus when receiving blue light. Instead, your eye may digest blue light as poorly focused visual static. This reduction in contrast may make it more difficult for your eye to process blue light, potentially contributing to eyestrain.

Still, there isn’t enough evidence to confirm that blue light directly leads to eyestrain. More high-quality studies are needed.

How to Limit Blue Light Exposure

The American Academy of Ophthalmology (AAO) recommends that you take the steps below to reduce digital eyestrain.

1. Practice the 20/20/20 strategy

  • While you’re using a device that emits blue light, stop every 20 minutes to focus on objects that are around 20 feet away. Study those objects for 20 seconds before you return to your up-close viewing.
  • Keep your eyes moist
  • Eye drops, such as artificial tears, and room humidifiers are all good ways to keep your eyes from becoming too dry and irritated while you’re using blue-light-emitting devices.

2. Use eyeglasses with the right prescription

Squinting at screens for long periods isn’t recommended for the overall health of your eyes. If you wear prescription eyeglasses to correct your vision, make sure you’re wearing a prescription intended for the distance between your eyes and your screen — ideally an arm’s length away. Most glasses are formulated for longer distances.

3. Adjust the blue light on your screen

To lower the risk of eyestrain and sleep disturbance, you may want to set your screens to a “night shift” setting with warmer tones. You can also purchase blue-light-filtering screens to slip over your computer screen when you’re working at night. The filter could cut the glare of your screen.

And a 2020 research study shows that they block 30 to 60 percent of blue light, though it isn’t clear whether blocking the blue will help preserve the sleep-wake cycle for those who use backlit screens before bedtime.

Too Much Screen Time:  Is it bad for kids?

Children and their phones, iPads and gaming devices are inseparable today. Most are growing up with a wide selection of electronic devices at their fingertips. They can’t imagine a world without the internet, smartphones and tablets.  Although, all that reading and playing games on their handheld devices may be harmful.  But it’s not just kids who are getting too much screen time. Many parents struggle with over use of screen time themselves.  So it’s important to understand how too much screen time could be harming everyone in the family.

Children can experience at least one of the following symptoms after being exposed to more than two hours of screen time per day:

  • Headaches
  • Neck/shoulder pain
  • Eye strain, dry or irritated eyes
  • Reduced attention span
  • Poor behavior
  • Irritability

Any of these symptoms could potentially affect academic performance and social interactions.

The worldwide rapid rise of nearsightedness has been linked to increased use of and exposure to electronic devices. However, spending more time outdoors, especially in early childhood, can decrease the progression of nearsightedness.

Blue Light can be harmful

The LED screens of computers and portable digital devices emit a broad spectrum of visible light. Most of these light rays are harmless, but a portion of the light emitted by these screens is relatively high-energy visible light called “blue light.”

Blue light has shorter wavelengths and higher energy than other visible light rays. Some laboratory research suggests certain bands of blue light may be harmful to the light-sensitive retina of the eye over time.

Blue light also plays an important role in regulating our body’s circadian rhythm. This basically is an internal clock that’s running in our brain and cycles between alertness and sleepiness at regular intervals over a 24-hour period.

Too much exposure to blue light at the wrong time of day can disrupt a person’s normal sleep/wake cycle, which can have serious health consequences.  Sleep disruption can be especially problematic for children, leading to daytime drowsiness and poor performance in school. Some authorities feel that disruption of the sleep/wake cycle also can eventually lead to weight gain and obesity-related health problems.

Research has shown that people who experience disrupted 24-hour cycles of sleep and activity also are more likely to have mood disorders, lower levels of happiness and greater feelings of loneliness.

How to cut back on screen time

  • Set a limit on daily screen time. Make it clear to your kids and stick to it.
  • Encourage your child to spend some of that screen-free time outdoors while it is still light.
  • Establish screen-free zones: For example, no smartphone use for anyone in the family in the car,  at restaurants, or at the dinner table.
  • No screens in the bedroom when it is time for bed. No exceptions.
  • As parents you can be a model for moderate screen use. Show your children, with your own behavior, how to live a rich, varied and healthy life where all habits are practiced in moderation.

It is also very important to teach your child good eye habits, below are few tips from experts:

  • You can set a kitchen timer or a smart device timer to remind them.
  • Alternate reading an e-book with a real book and encourage kids to look up and out the window every two chapters.
  • After completing a level in a video game, look out the window for 20 seconds.
  • Pre-mark books with a paperclip every few chapters to remind your child to look up. On an e-book, use the “bookmark” function for the same effect.
  • Avoid using a computer outside or in brightly lit areas, as the glare on the screen can create eye strain.
  • Adjust the brightness and contrast of your computer screen so that it feels comfortable to you.
  • Use good posture when using a computer and when reading.
  • Encourage your child to hold digital media farther away, 18 to 24 inches is ideal.
  • Create a distraction that causes your child to look up every now and then.
  • Remind them to blink when watching a screen.

Finally, it is very important to make sure your child gets a regular eye exam by a pediatric ophthalmologist or optometrist.  This will help monitor your child’s vision and eye health.

9 Tips To Relieve Digital Eye Strain

Online shopping has continued to grow this year, which means more people are spending more time on computers, tablets and phones. While the convenience of online shopping can’t be beat, it could be costing us sleep, giving us headaches, making our vision blurry…and even affecting our posture.

Digital Eye Strain

Digital eye strain (DES), also known as computer vision syndrome (CVS), is a consequence of spending two or more hours at a time looking at a digital screen. Nearly 30% of adults spend more than 9 hours each day using digital devices, while 25% of children use digital devices more than 3 hours a day.

This can result in dry or itchy eyes, blurred vision, eye twitches, headaches and even back and neck pain. Using digital devices for an extended period of time increases your tendency to lean into the device, as you try to focus or compensate for glare from reflected light (room lighting or windows). Holding these positions for long periods of time are what create the back and neck pain.

As for the many eye symptoms, they can come from

  • poor lighting
  • improper viewing distance from device
  • not blinking often enough
  • poor screen contrast
  • glare on the screen
  • UV blue light

To help you deal with DES, here are 9 tips to relieve digital eye strain.

9 tips to relieve digital eye strain

12/22/15


Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Increased Awareness for Saving Vision

The following is a survey done by Essilor (a French company that produces ophthalmic lenses along with ophthalmic optical equipment) and a large marketing research firm in the UK, YouGov. While the focus in on people living in the UK, the results would probably be similar to the US population. Even with increased access to the Internet, many people are still not aware of the risks associated with eye disease and what they can do to help retain their vision. Increased awareness of informational resources are important for saving vision.
saving vision
There are a number of websites with easy to understand information about taking care of your vision that I have listed under Resources to Help Save Vision at the bottom of this article. And while there are eye diseases that are hereditary, you can slow the onset and progression by making good lifestyle choices about smoking, diet and exercise. Your eye care specialist is also an excellent source of information about what you can to do reduce your risk of vision loss, at any age.

Increased Awareness for Saving Vision

A YouGov poll conducted with Essilor reveals that most Britons are unaware of damage to their eyes by surrounding objects, activities, and devices. This widespread lack of awareness means fewer people seeking methods of prevention and avoidance, and for those that are aware of risks, most are not informed of existing preventative measures.

The poll has shown* that many British people remain uninformed about the various ways in which eyes are damaged by common daily factors, despite evidence that eye health is affected by blue light, UV rays (reflected from common surfaces), diet, obesity, and smoking.
Of the 2,096 people polled, the percentage of respondents aware of the link between known factors affecting and eye health were:

  • Poor diet – 59%
  • Obesity – 35%
  • Smoking tobacco – 36%
  • UV light, not just direct from the sun but reflected off shiny surfaces – 54%
  • Blue light from low energy lightbulbs and electronic screens – 29%

More than one in ten people were completely unaware that any of these factors could affect your eyesight at all.
saving vision
72% of respondents own or wear prescription glasses but only 28% knew that there were lenses available (for both prescription and non-prescription glasses) to protect against some of these factors; specifically, blue light from electronic devices and low energy light bulbs, and UV light from direct sunlight and reflective surfaces.

76% admitted they haven’t heard of E-SPF ratings – the grade given to lenses to show the level of protection they offer against UV.

Just 13% have lenses with protection from direct and reflected UV light, and only 2% have protection from blue light (from screens, devices, and low energy bulbs).

Poll results showed that younger people were most aware of the dangers of UV and blue light, yet least aware of how smoking tobacco and obesity can affect your eye health. Within economic sectors, middle to high income people are more aware of the effects of smoking & obesity on eyesight than those with low income –

  • 39% of people with middle to high income compared to 33% of people with low income are aware of the impact of smoking tobacco.
  • 38% of people with middle to high income compared to 31% of people with low income are aware of the impact of obesity.

Awareness of the impacts of smoking and obesity on eye health is significantly higher in Scotland (47% & 49% respectively) than anywhere else in the UK (35% & 33% in England and 40% & 38% in Wales).
Essilor’s Professional Relations Manager, Andy Hepworth, has commented: “The lack of awareness about these common risks to people’s eyes is concerning. Not only would many more glasses wearers be better protected, but also many people who do not wear glasses would likely take precautions too, if made aware of the dangers and the existence of non-prescription protective lenses.”

To see the full results of the poll, please visit the Essilor website.

For more information on the protection offered from blue light and UV through specialist lens coatings, for both prescriptions and non-prescription glasses, please see here for UV & Blue Light Protection options.

*All figures, unless otherwise stated, are from YouGov Plc. Total sample size was 2,096 adults. Fieldwork was undertaken between 21st and 24th August 2015. The survey was carried out online. The figures have been weighted and are representative of all GB adults (aged 18+).

Resources To Help Save Vision
All About Vision
Macular Degeneration Partnership
National Eye Institute (NEI)
Prevent Blindness

10/16/15


Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation