Blue Light and Sleep


If sleeping issues arise, over exposure to Blue Light or High Energy Visible light may be partly to blame. Blue light is everywhere. It is emitted from the sun and gives the sky it’s beautiful blue color. It helps to keep us alert during the day promoting a healthy circadian rhythm. This is done through our eyes. The blue light stimulates specialized photoreceptor cells in our retinas called intrinsically photosensitive retinal ganglion cells (iprgs). These cells form the retino-hypothalamic tract sending nerve axons to the hypothalamus, the circadian pacemaker. By stimulating these cells blue light reduces melatonin levels inhibiting sleep and keeping us alert.

In today’s modern world, we are bombarded by blue light from our phones, tablets, TV screens, computers and LED lights. As much as we wish we could throw away some of these devices they are here to stay. Not to fret there are ways to minimize the harmful blue light affects.

Beyond turning off the screens an hour or two before going to bed we can also reduce the brightness on the screens, get a filter, use an app and purchase glasses with blue light protection coatings or tints available in prescription or non-prescription.

Apple has a feature on their Mac’s, iPhones and iPads called Night Shift that allows us to adjust the color of our screen based on the time of day. Microsoft includes a blue light filter called Night Light in its Windows 10 Creators Update. If our devices do not have these features we can buy blue light filters such as Eyesafe (Health-E), iLLumiShield, RetinaShield (Tech Armor), Retina Armor (Tektide), Frabicon and Cyxus.

In addition to reducing blue light on screens, make sure your overhead lights in the bedroom, night lights and reading lights are not LED and emit warmer longer wavelength light.

Not only does blue light affect sleep but there has been some evidence to suggest too much may cause damage to our retinas. This is because of the short wavelength property of blue light. It gets scattered more than other wavelengths making it difficult for our eyes to block. The scattering also creates more visual noise contributing to digital eyestrain.

Just like a lot of things in life too much of a good thing can be bad for us. Enjoy the modern conveniences with a few tweaks to keep our eyes healthy and feeling better while allowing us to hit the pillow and sleep well.

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After 12 years of practicing in Seattle, I had the fortunate opportunity to move to Alaska. Its people, beauty, wilderness and adventure makes me proud to call Alaska home. I graduated from the University of Washington and continued my education at Pacific University College of Optometry, graduating with honors in 2000. I am past president of the King County Society of the Optometic Physicians of Washington, member of Alaska Optometric Association, American Optometric Association, College of Optometrists in Vision Development, Neuro-Optometric Rehabilitation Association, and the Optometric Extension Program. I am currently working towards a Fellowship in the specialty areas of Neuro-Optometric Rehabilitation and Vision Therapy. I enjoy spending time with my husband and 2 children as well as serving the Anchorage community; Go Red for Women Alaska Chapter-American Heart Association, Alaska Brain Injury Network.


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