4 groups of people who need to know more — and how to help them understand why it matters
This article originally appeared in the September 2015 edition of INVISION.
Blue light is a big deal. Its impact on daily visual performance, eye disease and systemic health is becoming universally accepted, both in scientific literature and in the medical community. As eyecare professionals, we have a great responsibility to help our patients understand how blue light is affecting their lives — and provide them with solutions to minimize that impact.
Four kinds of people would benefit the most from a lens offering broad-spectrum blue-light protection:
➤ Patients with macular degeneration (or who are at high risk for developing the disease), as well as their family members, who are genetically predisposed.
➤ Heavy tech users. That’s anyone working on a computer or digital device, or under high-efficiency artificial light for more than three hours a day.
➤ Children have no natural lens pigment to protect their eyes. They also have shorter working distances when using their digital devices, which increases their blue light exposure.
➤ Post-cataract patients. They now have no natural protection, and since they’re also older, they’re at high risk for macular disease.
Here are four things they need to know:
Blue light is an increasing environmental hazard. We are used to thinking about protecting our eyes from the sun. But the proliferation of high efficiency light bulbs, flat screen TVs, computer monitors, laptops, tablets and mobile phones means we are continuously bombarded with high energy blue light at unprecedented levels, especially indoors and at night.
Blue light degrades the quality of your vision and strains your eyes. Because blue light bends more than other wavelengths (a phenomenon we understand as chromatic aberration), it is actually focused in front of the retina, causing blurring of images. And because short wavelengths scatter more than longer wavelengths (this is why the sky looks blue to us), blue light is responsible for most of the glare that we experience. When our eyes try to focus, they are fighting against these two phenomena, which results in eyestrain, especially when working on the computer and/or under artificial lighting.
Blue light is the major environmental factor contributing to retinal disease including macular degeneration. For years, eyewear has been designed to protect us from ultraviolet light. But most ultraviolet light is absorbed by the cornea and the lens before it can reach the back of the eye. Blue light is the highest energy light which actually reaches the retina and damages our macula. Peer-reviewed research going back decades shows that photo-oxidation by blue light in the 400-500nm range is most toxic to retinal cells. Over many years this can cause macular degeneration, the leading cause of blindness in the western world.
Exposure to blue light indoors and at night wreaks havoc on our circadian rhythms. There are special light-sensing cells in the back of our eye which control our sleep-wake cycle. They are especially sensitive to blue light in the 459-485nm range. In fact, blue light is a more powerful suppressor of melatonin than any drug known to man. When we are exposed to blue light in the evening hours and especially before bedtime, it is extremely disruptive to our sleep patterns.
According to the National Center on Sleep Disorders Research, sleep-related problems affect between 50 and 70 million Americans of all ages. Sleep disruption adversely affects attention, reaction times and mood. Even more alarming, study after study has linked exposure to blue light at night to several types of cancer (breast, prostate), depression, diabetes, heart disease and obesity. The current recommendation from the Harvard Health Letter is to turn off blue light sources at least three hours before going to bed, or to wear a blue-filtering lens.
Our understanding of blue light’s impact is growing every year. We’re sure to learn even more, but now is the time to offer our patients real, medically correct solutions to protect their vision and their overall health.
Dr. Adam S. Berger is an ophthalmologist specializing in retina surgery at the Center for Retina and Macular Disease in Winter Haven, FL. He is former assistant professor in the Deptartment of Ophthalmology and Visual Sciences at Washington University in St. Louis, MO, and he is a widely published author and lecturer.