Expert ADVICE
DR. MARK RASMUSSEN, OD Optometric Physician 1651 Galisteo St, Suite 1 505.983.7746 ultimateeyecaresantafe.com
L
ately, we’ve been getting a lot of questions about blue light. Let’s see if we can shed some light on the issue.
First of all, what is blue light? Sunlight contains red, orange, yellow, green and blue light rays. Combined, this spectrum of colored light creates what we call ‘white light’ or sunlight. Light rays that have relatively long wavelengths contain less energy, and those with short wavelengths have more energy. Rays on the red end of the spectrum have longer wavelengths and, therefore, less energy. Rays on the blue end of the spectrum have shorter wavelengths and more energy. Approximately one-third of all visible light is considered high-energy, or blue light. SOME KEY THINGS TO REMEMBER ABOUT BLUE LIGHT: 1. Blue light is everywhere. Sunlight is the main source of blue light, but there are many man-made, indoor sources of blue
What is blue light and does it cause damage?
light as well, including fluorescent or LED lighting, and flat screen televisions. Most notably, the display screens of computers, electronic notebooks, smartphones and other digital devices emit significant amounts of blue light. The amount of blue light emitted from these devices is only a fraction of that emitted by the sun, but the amount of time people spend using these devices and the proximity of these screens to the eyes leads to concerns. 2. The eye is not very good at blocking blue light. Virtually all blue light passes through the cornea and lens, reaching the retina. 3. The fact that blue light penetrates the retina (the inner lining of the back of the eye) is important, because lab studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina. This causes impairment resembling macular degeneration, which can lead to permanent vision loss. 4. Blue light scatters more easily than other visible light and thus is not as easily focused. Looking at computer screens and other digital devices can contribute to digital eye strain. 5. Blue light protection may be even more important after cataract
surgery. If you are about to have cataract surgery, ask your surgeon what type of intraocular lens (IOL) will be used to replace your cloudy natural lens, and how much blue light protection the IOL provides. You might benefit from eyeglasses that have lenses with a special blue light filter, especially if you spend long hours in front of a computer screen or other digital devices. 6. Not all blue light is bad. It’s welldocumented that some blue light exposure is essential for good health. It boosts alertness, helps memory and cognitive function, and elevates mood. Blue light is also important in regulating the body’s natural wakefulness and sleep cycle. However, too much blue light at night can disrupt this cycle, potentially causing sleeplessness and daytime fatigue. Many lens manufacturers have designs to help limit excess blue light. There are tinted lenses and coatings that can be put on your eyeglasses to help. Make an appointment with Dr. Mark Rasmussen for a comprehensive eye examination. It’s a good way to monitor eye health, maintain good vision, and keep track of your blue light protection needs. Article courtesy allaboutvision.com.