Like ultraviolet radiation, blue light—the part of the visible light spectrum with the shortest wavelengths and highest energy—can both harm us and help us. Below are some interesting facts about blue light and how it impacts our health, from a Raleigh eye doctor.
Many people are aware that LED lights and flat-screen TVs emit blue light that can damage our eyes. However, we receive most of our blue light exposure outdoors, from sunlight. The reason computer and phone screens are so harmful to our eyes is that, while they only emit a fraction of the blue light emitted by the sun, they are usually very close to the user’s face for extended periods of time.
Research has revealed that blue light penetrates all the way to the retina, the sensitive inner lining in the back of the eye. Laboratory studies have also shown that too much exposure to blue light can damage the light-sensitive cells in the retina, causing changes that resemble those of macular generation (which leads to permanent vision loss). Although more research is needed to determine how much natural and man-made blue light is “too much” for the retina, many eye care providers are concerned that blue light exposure from digital devices might increase our population’s macular degeneration rate.
Our eyes are very good at blocking UV rays from reaching the light-sensitive retina at the back of the eye. Even if you aren’t wearing sunglasses, less than one percent of UV radiation from the sun will reach your retinas, as long as your corneas and lenses are in good working order. (Note: this doesn’t mean you’re free to skip the sunglasses. Even that small percentage of UV radiation can cause a lot of damage.) With all that said, the same is not true when it comes to blue light. Virtually all visible blue light passes through the lens and cornea and reaches the retinas.
If blue light is so bad for our eyes, why don’t we wear blue-light cancelling glasses or contacts all the time? Because we actually do need some blue light to be healthy. Research has shown that high-energy visible light, such as blue light, boosts alertness, helps memory, improves cognitive function, and elevates mood. In fact, blue light is even prescribed as a treatment for those affected by Seasonal Affective Disorder (SAD), also known as Seasonal Depression. The light sources for this therapy emits bright white light that contains a significant amount of HEV blue light rays.
Blue light is also very important in regulating the circadian rhythm, the body’s natural wakefulness and sleep cycle. If you get enough blue light during the day, your body is more likely to be well-rested at night. But if you get too much blue light at night (from reading a tablet computer or e-reader at bedtime, for example), your cycle could be disrupted.
If you are concerned that you are receiving too much blue light, stop by Raleigh Eye Center. Our licensed opticians can help you choose a lens or other vision correction option that will help you view digital devices with minimal eye strain. To schedule an appointment with a Raleigh eye doctor, click here.