Because there is both:
1. a reason to be concerned about the potential harm to the eyes from a cumulative lifetime overexposure to high-energy visible light as well as UV radiation, and
2. evidence exists that some degree of blue light exposure is required for good health,
the question is: how much should eye care providers worry about blue light exposure, and what is the right amount of blue light protection to recommend?
According to Tailored Lighting, Inc., a leading manufacturer of light sources used for blue light therapy, 90 minutes of close exposure to the lights used for this type of therapy is the equivalent of taking a 10-minute walk outdoors at midday.
In other words, the HEV exposure from sunlight outdoors is nearly 10 times as potent as these bright indoor light sources specifically designed to emit blue light without attenuation.
While much is being discussed these days about the potential danger of blue light emitted from indoor lighting, computers and other portable electronic devices, the fact remains that the best way to significantly reduce unwanted blue light exposure is to discuss the radiation dangers of outdoor sunlight with your patients and make sure they wear protective sunglasses on a daily basis when outdoors during daytime.
And there’s plenty of room for improvement when it comes to making sure patients are adequately protecting their eyes from the sun. According to The Vision Council’s 2014 Sun Protection Survey, 27 percent of adults “rarely or never” wear sunglasses when outside — and 46 percent said they wear sunglasses “only when it’s sunny out.” Even worse, in a 2013 survey by The Vision Council, less than half of parents (48%) encourage their children to wear sunglasses outdoors.
And while it’s true HEV-blocking eyeglasses prescribed for computer use and general indoor wear will provide a limited supplemental attenuation of blue light exposure, some of these lenses can have cosmetic issues (a visible tint in the lens) that many wearer may find unsatisfactory. Also, there is no definitive answer at this time regarding how much computer eye strain is caused by blue light exposure. It’s likely accommodative fatigue, convergence stress, dry eyes, and other factors may play a larger role than blue light exposure in causing computer vision syndrome and computer eye strain symptoms.
To make the biggest impact on protecting your patients eyes from the harmful effects of the potential dangers of blue light, start with protecting their eyes from sunlight outdoors.