Blue Light: Harmful?

The short answer is “yes and no”; we’re still gathering information and studies are ongoing to determine the exact nature and extent of “blue light” damage to the eyes.  We’ll get more into that, but first…what is this blue light exactly? Well, it’s not specifically blue light, per se, it’s technically High Energy Violet (HEV), and it comprises a section/band of wavelengths in the visible light spectrum right next to the harmful/invisible ultraviolet (UV) wavelengths (the ones that can cause damage to the skin in the form of sunburns and damage structures in the eyes over time).  Since HEV is right next to UV in the light spectrum, it could theoretically be pre-disposing eyes to the development of things like cataracts, glaucoma, macular degeneration, etc.


We’re exposed to most HEV through regular sunlight and when viewing many digital device screens (cell phones, computer screens, television screens, etc.)  With the dramatic spread of digital device use recently and the increase in digital device screen time from a very young age, researchers are concerned that the years of cumulative exposure are harming our eyes.


I worked two jobs in college and eventually took the plunge on my very first cell phone during my sophomore year (a flip phone!), but kids these days are getting their first phones earlier every year (I know some pre-teens with phones!), and many schools have replaced paper textbooks with iPads and the like.  This equates to years more screen time (and HEV exposure) than people had experienced just a few years ago.


The optical industry has started marketing campaigns pushing for customers to purchase “blue light filters” in glasses to protect the eyes from HEV light.  Even as recently as a few years ago, optical companies starting offering blue-blocking technologies included those by Nikon (SeeCoat Blue), Essilor (Crizal Prevencia), PFO Global (iBlu coat), HOYA (Recharge), VSP (UNITY BluTech) and Spy Optic Inc. (Happy Lens).  Even more have cropped up since then.  Studies are ongoing to determine just how serious this blue light threat is, but preliminary studies seem to indicate that the eyes are indeed susceptible to damage from some wavelengths of blue light.  If you’d like to read more about HEV and get some links to recent studies, check this one out:


In addition, have had patients report greater visual comfort with extended digital device viewing when they used glasses with HEV filter technology than they had in the past with their conventional lenses.  So if you want a little more comfort with your digital devices and want to protect your eyes until we sort out exactly the extent of the damage to your eyes from years of blue light exposure, you should consider adding blue light filters to your next pair of glasses.  Have a great day!



Benjamin D. Snyder, O.D.