Why Should You Care About Blue Light?
 
Overexposure to blue light (aka high-energy visible light) is potentially dangerous to the eye. Though it has some beneficial qualities—namely coordinating our circadian rhythm and helping with mood—recent research is indicating that blue light can be damaging to the macula.
In this day of ubiquitous digital devices and screens, which emit high levels of blue light, blue light is becoming a focus in the eyecare field. What’s the deal with blue light and why should you be talking to your patients about it (and blue light filtering lens products)? We asked two optometrists for their thoughts.
 
 
How much of a risk does exposure to blue light pose to patients, and should ECPs be emphasizing it along with UV and digital eyestrain issues.
 

GARY MORGAN, O.D., EYE TECH EYE ASSOCIATES, PEORIA, AZ: There is a common misconception on which type of light is more harmful to the eye, UV light or visible light. UV light can cause cancers of the eyelid, pinguecula, pterygium, photokeratitis, and contribute to cataract formation. However, these conditions generally do not cause blindness in developed countries. It is important to understand that UV light does generally not reach the retina as most of UV-B (below 295 nm) is blocked by the cornea, and remaining UV-B and all of UV-A (below 400 nm) is blocked by the crystalline lens. 
On the other hand, visible light is incident on the retina, providing light for vision.  Blue light is considered from 400-500 nm. Cumulative lifetime exposure to blue light (400-500 nm) causes photo-oxidative stress in retinal cells that is a contributing factor to the development of age-related macular degeneration (AMD).
Of concern is the exponentially increased amount of blue light people of all ages are now exposed to. Computer screens, televisions, laptops, smart phones and tablet computers are all strong emitters of blue light. Additionally, we have changed the way we light our homes.  Incandescent bulbs have been replaced with CFL bubs, also strong emitters of blue light.  So while exposure to blue light is not new, the amount of exposure time each day has dramatically increased.
 
In my opinion, it is imperative that we as eye care providers are fully educated on the sources of blue light and it’s effects on long term ocular health as well as everyday vision. While we have known that blocking blue enhances contrast by diminishing chromatic aberration thus reducing glare, blue light protection is a new concept. The best of today’s new lens technology for blue light protection filter blue light without altering color perception, and meaningfully protects along the entire blue light spectrum, 400-500 nm.
 

KIRK  SMICK. O.D., CLAYTON EYE CENTER, MORROW, GA: There’s already a bit of research on this, and there will be quite a lot more to come.
The one thing we don’t have is a big history on this. So we’re not in “wait and see” mode, we’re in a “we’ll find out” mode, and the reason we don’t have the big history is that we didn’t have all these iPads and iPhones before, and the way the lighting industry is changing so quickly that we’re now being exposed much more to these particular wavelengths of blue light—that, if the research is accurate, 20 years from now there’s going to be a lot of people walking around with damaged retinas. And maybe a higher degree of macular degeneration that we’ve experienced heretofore.
So I think what a lot of us are doing – we see the research, we know protecting our patients’ eyes with blue light blocking lenses certainly can’t cause any problem to the patients. So it’s like a “do no evil” kind of thing where, there’s nothing to lose, and probably a lot to gain.
 
Do you discuss blue light with every patient, or do you look for specific age groups/computer use? How do you approach the subject of blue light with patients?
 
DR. SMICK: I have a conversation in the exam room who are exposed in particular, certainly if they work on the computer all day or the kids we know they play their games on these electronic interfaces, we know they are exposed much more to this potentially dangerous blue light than they were 10- to 15 years ago, so I think it’s really important for those groups to protect their eyes from any possible future damage.
This morning I had a lady who doesn’t use a computer at all, so she might not be much at risk, so you can’t really say EVERYBODY should be wearing these, but there are groups of people out there that we need to protect.
We know have the advantage of lenses coming out – and more to come – that are attractive, and coatings that can block this blue light. I mean, they should be getting an AR coating anyway, and now there are those that also offer protection from blue light as well.
 
 
DR. MORGAN: As we are immersed in technology, I feel it is appropriate to discuss the dangers of blue light with patients of all ages. For children, I engage parents in the discussion on their child’s electronic device usage. In our area, many schools have gone to using textbooks on tablet computers, in addition to many kids now carrying smartphones. 
This constant blue light exposure, while inflicting long-term damage to the retina, can also affect our ability to fall asleep. Exposure to these wavelengths after dark will affect our internal clock, causing the pineal gland to suppress the excretion of melatonin, our sleep hormone. This affects our ability to fall asleep. In kids this can lead to loss of focus and concentration, irritability, and hyperactivity, sometimes being mistaken for symptoms of ADHD. For adults, obviously we have many of the same exposure issues of blue light after dark.  It has also been shown that sleep disturbance in adults can lead to chronic conditions such as diabetes, obesity, heart disease, depression, stroke and cancer. 
My practice is located next to a retirement community so many of the patients I see are elderly. The eye contains natural protection n the form of Ocular Lens Pigment (OLP).  OLP is the result of a decades long process that involves oxidative polymerization of the chromophore 3-OH-kynurenine from light passing through the lens. As we do not form any significant OLP until about age 40, and significant protection is not afforded until age 70 or later, we are essentially unprotected from blue light from childhood through our adult lives. 
 
 
Is there anything else you’d like to add or advice you have for other ECPs, based on what you are doing to help your patients protect their vision from blue light.
 
DR. SMICK: There is literature available on the science behind this. Doctors like science. I would encourage doctors to look at the science, and get involved, and talk to the patients in general about protecting their eyes. I think we’ve done a good job with UV. We’ve embraced it as a profession. This is just a natural accompaniment to that.
As the information grows, we’ll become more and more savvy about this. The bottom line is this: Although to what degree we still don’t know, but there is some risk inherent to what’s going on out there, and we have an obligation to inform our patients about it.
 
DR. MORGAN: Blue light is a hot topic with dozens of reports being presented by the media in print, on television, and online. I advise my colleagues to be fully versed in the dangers of blue light, be prepared to educate patients and answer their questions, and provide protective eyewear solutions for them.  When I start a blue light conversation now compared to a year ago, I am getting many patients stating, “yes, I have heard about that”.    
 
For more information on blue light, see the October 2014 issue of Eyecare Business and it’s supplement, “The Business of Blue Light.”