What is blue light? 

Sometimes referred to as HEV (high energy visible) light, blue light rays have the shortest wavelengths and penetrate deep into the eye.   Blue light is everywhere.  These HEV light rays are what makes the sky blue.  Although we get most of our blue light exposure from outdoors during daylight hours,  our new lifestyles have increased our blue light exposure.

Blue Light Chart

Why are we now concerned about blue light? 

The majority of our blue light exposure comes naturally from sunlight.  Now we have added new blue light sources to our lifestyle through digital devices, computer and TV screens as well as LED lighting.  Although our exposure from these devices is a fraction of what we encounter from daylight, our usage and proximity to them increases the possibility of damaging effects on the eye.  Studies show that up to 82% of people use digital devices for more than two hours per day, and 52% of use us two devices simultaneously.   Unfortunately, it is yet to be determined how much natural and man-made blue light is “too much” for the retina.

Blue light also regulates our circadian rhythm by suppressing our bodies natural release of melatonin which controls our sleep patterns.  As a result, some blue light is important during daytime hours.  Too much blue light exposure late at night can potentially result in sleepless nights and daytime fatigue.

Glasses and Computer ImageWhat is the impact of blue light on our wellness? 

A big concern is digital eye strain.  Blue light scatters more easily than other visible light reducing contrast and causing strain when using computers and devices.  Our natural lens in our eyes is good at blocking UV rays, but not blue light.  This is even more of a concern for people who have had cataract surgery.  Prolonged digital eye strain can lead to headaches, dry eye and computer vision syndrome. 

Like ultraviolet light which falls on the non-visible spectrum, blue light exposure could damage the retina causing long term vision issues like macular degeneration and cataracts.

As noted previously,  a disruption in our natural sleeps patterns could lead to fatigue, reduced attention span and irritability.  This is especially true with children when they have more than two ours of screen time per day.

What can we do to reduce the effects of blue light exposure? 

If your lifestyle or work requires prolonged computer use, practice the 20/20/20 rule.  It’s simple: every 20 minutes look 20 feet away for 20 seconds.  This also helps to reduce neck and shoulder strain.

Avoid digital device usage 1 hour prior to bed.   This could improve your ability to fall asleep faster and result in better rest reducing your fatigue the next day.

Tom Davies Sterling SunInvestigate blue filtering screens or apps for your computers and digital devices.  This may also help to reduce your eye strain.

Wear a good pair of sunglasses when outdoors.  Most quality sun lenses will block blue light as well as UVA, UVB & UVC for reflective ultra-violet light.

There are now prescription lens materials and special anti-reflective coatings that can reduce your exposure to a specific blue-violet range of light which is believed to be the most harmful.  These options allow the good blue light to flow through your lenses, and have a low impact on your circadian rhythms.  These choices are great for individuals who have jobs that require full days of computer or device usage.  Remember – traditional over-the-counter or yellow tinted lenses could block all blue light from entering the eye and affect your sleep.

To learn more about the new blue light lens options, click here.