The visible spectrum of light produced by our sun has a range of wavelengths within the range that our eyes can see. Red has the lowest wavelength and the least energy in the spectrum of visible light. On the other end of the spectrum is more high-energy blue light which has a shorter wavelength and is thus higher energy.
While the sun is the most common source of visible light it is not the only type of light we can see. Nor is it the only source of light that can affect our eyes. Many modern-day light fixtures and digital devices also emit light that can affect our eyes.
Blue Light Can Be Both Good And Bad
Sometimes referred to as “Blue-Violet” or “Violet Light” this shorter wavelength of visible light is very close to ultraviolet radiation, which exists on the spectrum just beyond what our eyes can visually see. Though it can still affect us on a cellular level.
Chances are you’ve heard about and experienced the effects of UV rays on your skin. This high-energy wavelength of light is capable of affecting many different types of cells. Some in a beneficial way and some in a harmful way.
For example, small doses of UV light from the sun or a tanning bed can cause your skin cells to release melanin which produces a dermal layer tan. Yet excessive exposure to UV light can even cause a bad sunburn. When it comes to the eyes, something like a bright day in winter can cause UV light reflecting off the snow to damage cells in the eye. When this happens it’s called “Snow Blindness” which is technically called “Photokeratitis.”
Now, this isn’t to say that ultraviolet light is all bad. When small doses of blue light from the sun help our bodies produce a Vitamin D 3. Also known as calciferol, this a fat-soluble vitamin that helps your body absorb calcium and phosphorus. It also helps with certain cellular functions in the brain.
Blue light is also used in certain treatment plans for things like seasonal affective disorder and other circadian rhythm disorders. These treatments call for exposing the individual to specific wavelengths of artificial blue light to help rebalance the brain’s natural functions.
Blue Light From Electronics And Digital Display Screens
It might surprise you to learn that there are artificial sources of blue light all around you. This includes things like fluorescent light fixtures, LED lights, and many flat-screen televisions. Most display screens such as computer monitors, electronic notebooks, tablets, and smartphones also emit artificial blue light.
While these electronic devices only produce a tiny fraction of the blue light that the sun does, they can still have an impact on your health. Especially the health and function of your eyes. For some individuals, blue light exposure in the evening hours can even affect sleep hygiene and sleep quality. This is related to the amount of time we spend viewing these blue light devices. Especially those that we put close to our face.
The human eye isn’t very good at filtering out blue light. There are even some structures inside the human eye, like the sensitive retina at the back of the eye that are particularly vulnerable. Unfortunately, most of the sunglasses sold at the consumer level do very little to help filter out blue light. Though some UV protection sunglasses on the market will help.
How Does Blue Light Effect Eye Health?
It’s estimated that around 70% of adults in the United States experience some degree of eye strain related to overexposure to digital media. This can also lead to issues like blurred vision, and eye strain-related headaches. There’s also a growing body of research that has found a connection between blue light exposure in the evening and problems falling asleep or staying asleep.
Can Blue Light Increase The Risk For Macular Degeneration?
Macular degeneration is a condition that causes a loss of acuity in the central field of vision. Blue light can penetrate to the retina itself at the rear of the eye. This could potentially damage light-sensing nerve cells, which can contribute to macular degeneration symptoms in the long run.
However, this is arguably a new area of research. At this time, it’s not fully known how much blue light is too much. Especially when you consider that macular degeneration risk increases with age.
How Much Does Blue Light Contribute To Digital Eye Strain?
Blue light is a high energy form of visible light with a short wavelength. Digital screens that emit a high amount of blue light essentially creates “Visual Noise” which can contribute to eye strain.
How Can I Reduce Blue Light Exposure And Eye Strain?
Unfortunately, the pace of modern-day life has us using digital devices more-and-more. It also doesn’t seem to be changing any time soon. While you might not be able to significantly reduce your exposure to digital displays screens for work and other essential activities, you might want to try cutting back in your leisure time.
Ideally, you want to avoid smartphones and tablets at least an hour, if not two hours before going to bed. This may help you to fall asleep better and stay asleep throughout the night.
It’s also worth noting that increasing awareness of the problems caused by blue light has led to things like “Digital Protective Lenses and other screen filters to help reduce the amount of artificial blue light that affects the eyes. A growing body of research suggests that yellow-tinted lenses that block blue light with wavelengths of 450 nm or less can help reduce digital eye strain symptoms.
Blue Light Reduction Might Be Needed After Cataract Surgery
New research suggests that the short-wavelength blue light can complicate certain types of cataracts surgery. This is especially concerning with Intraocular lens treatment. Also, knowns as IOL, you might need to wear eyeglasses with a special blue light filter. This is especially important if your lifestyle or profession calls for you to spend a lot of time in front of digital display screens.