By Dr. Cynthia PayneWe are exposed to blue light daily. The sun emits both UV light and blue light. The high-energy blue-violet light is in the shorter wavelength of the light spectrum. In our businesses and homes, the newer, more cost-efficient lighting such as LED lighting and compact fluorescent lighting give off blue light. LED lighting emits more blue light than CFL lighting. This is significant because our TVs, computer monitors, smartphones and tablets utilize LED lighting to give a better image.
Blue light has many benefits. It is essential for the circadian rhythm of our body (setting our sleep/wake cycle). Our circadian rhythm is important for good health and our well-being. Blue light affects the circadian rhythm by suppressing melatonin secretion.
Blue light has been used therapeutically to treat some types of skin pre-cancers, bulimia, PMS and mood disorders such as depression. Because it also increases body temperature and heart rate and decreases sleepiness, it can increase alertness. This is significant with blue light exposure at bedtime. It can take longer to fall asleep and affect quality of sleep.
As with UV light, the effect of exposure to blue light is cumulative. Blue light reaches deeper into our eyes than UV light and may be more damaging to the retina. TV screens and light fixtures are going to give us more indirect exposure to blue light, while computer monitors, tablets and smartphones will give us greater exposure to blue light. The closer it is to our eyes, the greater the exposure and risk to the retina. A 2012 study by Dr. Celia Sanchez-Ramos, published in Photochemistry and Photobiology, showed that blue light damaged the retinal pigment epithelial cells. This would increase our risk of developing age-related macular degeneration. Age-related macular degeneration decreases or destroys our central vision and is one of the leading causes of blindness in people over the age of 60. Because the effect is cumulative, children are at higher risk. Children are using smartphone and tablet technology to read and play games, and because their arms are shorter, the devices are closer to their eyes than they would be to an adult’s eyes.
There are several options to protect our eyes from blue light. There are a few apps and screen protectors available for smartphones and mobile devices to decrease blue light. F-lux is an app for the iPhone and iPad. Blue Light Filter for EyeCare and Twilight has been developed for Android devices. Another way to decrease blue light exposure is to decrease the brightness of the light on your device from the settings menu.
Ophthalmic lens manufacturers have developed lenses and coatings specifically for protection from blue light exposure. Trendsetter Eyewear offers prescription lenses with anti-glare coatings that are combined with blue light blocking technology. These lenses are not like the orange-brown blue blocker lenses that have been used for sunglasses. They are a cosmetically more appealing clear. There are some non-prescription computer glasses available that have a light blue blocker tint combined with an anti-glare coating to help protect eyes.
Another way of protecting our eyes is to help replenish the nutrients that our retina needs to be healthy. We can do this by using a quality multivitamin daily and eating a diet rich in dark green leafy vegetables such as kale, spinach and turnip greens. We also get macular pigment nutrients from free-range egg yolks, winter squash and corn.