Blue light is a type of visible light with a high energy wavelength. It is emitted from digital screens like computers and phones as well as artificial lighting. While blue light is not conclusively proven to damage eyes, extensive exposure can cause eye strain and disrupt circadian rhythms. To protect eyes, experts recommend taking breaks when using screens, blinking frequently, following the 20-20-20 rule, and using blue light filtering lenses. More research is still needed to understand blue light's long term effects on vision and health.

1. Exposure to Blue Light and
Eyesight Health: Everything You
Need to Know
If you spend any significant amount of time on your computer or smart device,
you probably have at least heard about the research on blue light and
eyesight health. Even if you haven’t, chances are that these (and other) blue

2. light devices, along with the “blue” light they emit, affect your life in some
pretty significant ways.
But when we talk about the connection between exposure to blue light and
eyesight health, opinions about it’s danger (or lack thereof) are all over the
place. It only takes a few minutes of searching for information on blue light
and eyesight health to begin formulating emotionally heavy internal questions
like:
Is it harmful? Is it not harmful? Should I worry? Should I limit screen time?
Should I buy glasses that promise to filter out the light? Should I go back to
using oil burning lamps and handwriting letters to send in the actual mail?
Educatedly Guessing About the Effects
of Blue Light on the Eyes
Don’t get us wrong, these are all very valid questions. Well, except for maybe
the last two! The problem is that we can’t answer any of them with certainty at
this time. Medically speaking, we just don’t know enough about blue light yet.
We don’t know the lasting effects of blue light on eyesight health, and we
won’t for at least another 20 years…while our current (digital) generation
becomes test subjects whether, and just like exposure to blue light, we know it
or not.
In lieu of “knowing for sure” when it comes to blue light and eyesight health, it
is extremely important to discuss what we know about it right now. This way,
you can make an informed, educated decision for yourself and your family
about the role of blue light devices in your lives, as well as the potential effects
of blue light on eyesight health for everyone in both the short and long-term.
Let’s start by talking about the science of HEV Blue Light.
What is HEV Blue Light?

4. The Visible Light Spectrum Graphic Image Designed by Fulvio314
So, just what is HEV Blue Light? HEV stands for “high-energy visible,” and it
refers to the vibrational frequency, or wavelength, of the color blue on the
visible light spectrum. HEV blue light has one of the shortest, yet highest
energy wavelengths on the visible light spectrum. Versus red light, which has
a longer wavelength and lower energy output, HEV Blue Light wavelengths
flicker more easily and for longer amounts of time. The flickering blue light
wavelengths create a glare that affects clarity and contrast.
What are Blue Light Devices?
Actually, largest blue light emitting device in our solar system is the sun. When
the shorter, higher energy blue wavelengths collide with air molecules, blue

5. light scatters all over the place. This is why the Earth’s sky looks blue and not
green, purple or red.
Of course, sunlight is extremely important to the health and wellness of
humans. What is more, the atmospheric results of the most amazing of all
natural blue light devices allows us to regulate our bodies’ natural sleep and
wake cycles, or circadian rhythms. Other positives effects of natural blue light
devices like the sun are:
 Heightened Reaction Times
 Elevated moods
 Boosted alertness
 An Overall Increased Feeling of Well-Being
 Growth and Development of Vision in Children
 (Potentially) a Decrease in Myopia/Nearsightedness
What is an Artificial Blue Light Device?

6. An artificial blue light device mimics the sun’s effect on our eyes, even if to a
lesser extent than staring straight up into the sky on a bright, cloudless day…
which we do not recommend doing anymore than we recommend staring at or
into an artificial blue light device every waking moment! An artificial blue light
device includes:
 Fluorescent lighting
 CFL (compact fluorescent light) lighting
 LED lighting
 Flat screen televisions (LCD/LED, etc.)

7.  Computer monitors, smart phones, and tablet devices, etc.
So why do we currently know that is it not good to be looking at or into or even
with the assistance of these artificial HEV blue light sources all the time?
Well, and among other reasons, our eyes’ natural filters are incapable of
providing sufficient protection from the sun’s blue light. This means, by default
really, they will have issues protecting themselves (and the rest of us!) from
the blue light that emanates from the devices we’ve created.
Does Blue Light Damage Eyes?
Now to the million dollar question: Does blue light damage eyes? Well,
according to David J. Ramsey, MD, PhD, MPH, the Director of Ophthalmic
Research at the Lahey Hospital & Medical Center, we must take the size of
the blue light source into account when beginning to formulate an answer to
this very complex question…
“It all comes down to this: consumer electronics are not harmful to the retina
because of the amount of light emitted. For example, recent iPhones have a
maximum brightness of around 625 candelas per square meter (cd/m2).
Brighter still, many retail stores have an ambient illumination twice as great.
However, these sources pale in comparison to the sun, which yields an
ambient illumination more than 10 times greater! High-intensity blue light from
any source is potentially hazardous to the eye. Industry sources of blue light
are purposely filtered or shielded to protect users.”

8. Fatoumata Yanoga MD of The Ohio State University agrees, but adds:
“These sources contain a small amount of blue light compared to the sun, but
just think of the amount of time we spend on these devices and how close we
put our faces to them. The fear is that it’s causing cumulative damage over a
long period of time, as it passes through the cornea and lens and reaches the
retina. One animal study showed blue light can cause toxicity to retina
photosensitive cells, which are irreplaceable. The theory is that if it’s toxic to
animal models then it can be to human beings (A large study that evaluated
blue light in the rate of cataract formation in humans ended up being
inconclusive.”
However, and as Dr. Yanoga goes on to say, “Damage to the retina can cause
vision problems such as age-related macular degeneration, which can lead to
permanent vision loss.”

9. The Connection Between Artificial Blue
Light and Eye Strain
For all we don’t yet know about whether or not blue light seriously damages a
human being’s eyes in the long-term, we do know that a connection exists
between artificial blue light and eye strain/fatigue. “Digital Eye Strain” is the
term for the harmful effects of living in front of a screen.
Specifically, Prevent Blindness discusses a study that shows blue light from
computer screens and other digital devices can decrease contrast, which
leads to eyestrain. Whether spending 8 hours straight at work, or just 2-3
hours in the evening, our eyes struggle to see through the glare and harmful,
artificial blue light. Digital eye strain is also caused by a lack of sufficient
blinking while looking at a digital screen.
Needless to say, the more time a person spends staring at and into digital
devices that produce artificial blue light, the more of a chance they can suffer
from digital eye strain.
The Connection Between Blue Light and
Circadian Rhythm

10. Even more research is being conducted on the connection between artificial
blue light and circadian rhythm. This includes a large NIMH study that found:
“If blue light is excessive, especially at night when melatonin production
peaks, it can not only damage the retina through the ocular surface, but can
also stimulate the brain, inhibit melatonin secretion, and increase
corticosteroid production, thereby destroying hormonal secretion and directly
affecting sleep quality”
Additionally, Harvard Researchers found that blue light suppresses melatonin
secretion more so than green, and other forms of light. Specifically, at 6.5
hours’ exposure to blue and green light of comparable brightness, the blue
light suppresses melatonin for almost twice as long as green, and it also shifts
circadian rhythm for almost twice as long as the green light. Disruption of the
circadian rhythm can cause psychological and behavioral changes leading to:

11.  Weight Gain
 Impulsivity
 Slower Thinking
 Motor Skill Issues
So, we can safely deduce at this point in time that blue light and circadian
rhythm are probably related. What is more, it appears that light of any kind has
a negative effect on circadian rhythm and thus, sleep. Blue light simply
enhances the overall negative effects.
How to Protect Your Eyes From Blue
Light Exposure
Now let’s talk about how to protect your eyes from blue light exposure…
because it never hurts to take a bit of extra care now, if it might help preserve
your eyesight in the long run! There are several easy ways to protect your
eyes from blue light exposure:
1. Spend less time in front of a screen and, if possible, high levels of artificial
light in general in the evenings. Allowing your body to realign itself with the
Earth’s light cycle can help reset your circadian rhythm.
2. Make it a conscious point to blink frequently when looking at any type of digital
screen. Digital eye strain is caused, in part, by the severe lack of blinking that
occurs for most human beings when we stare at these screens! Every time we
blink, our eyelids spread a mixture of oils and mucous secretions across the
surface of the eye to keep our eyes from drying out. Blinking also keeps eyes
safe from potentially damaging stimuli, such as bright lights and foreign bodies
like dust.
3. Apply the “20-20-20” rule. This means every 20 minutes, we spend 20
seconds looking at something approximately 20 feet away. This allows our
eyes to refocus, prompts natural blinking and stretches the eye muscles,
thereby reducing eye fatigue.
4. If you wear prescription glasses, you can also look into purchasing a blue light
filtering anti-reflective coating for your glasses. This coating filters out roughly

12. 80% of blue light and reduces eye strain and digital fatigue. Glasses that filter
blue light are also available for those who do not require a prescription.
The Best Optometrists in North Phoenix
When you choose Tatum EyeCare for you vision health and fashion needs,
you are choosing optometrists in North Phoenix who are invested in our
clients and community. We’ve proudly served the Valley of the Sun for over 20
years. We are here to answer any questions about our services you might
have. Come see for yourself how Tatum EyeCare reframes customer service
and optical expertise for everyone!