Blue light filter – Ask Eye Doc

Written By: Dr. Stephanie Mulick, O.D. Is Blue light Good For you? Blue light is very beneficial when it comes to regulating our circadian rhythm, our energy and mood. Most blue light is emitted from the sun. Blue light helps us wake up and stay alert throughout the day. When the sun goes down our bodies produce melatonin which helps us sleep. When I lived in Chicago for Optometry school it was common for people to develop Seasonal affective disorder (SAD). That is because during this time there was less exposure to blue light. In fact, people would use special High-energy visible (HEV) light lamps to help prevent symptoms of SAD. Modern-day technologies such as cellular phones, computers and tablets expose our eyes to more blue light than ever before. The fact is, many of us spend hours on electronic devices and at close proximity to our eyes. This results in more penetration of blue light into our eyes. Why does this matter? Well, first off let’s discuss the light spectrum. The shortest wavelengths of visible light are blue and violet, which have the highest amount of energy also known as high-energy visible light or HEV. As far as the eye is concerned these short wavelengths of light penetrate the ocular structures much easier than longer wavelengths of light red, orange and yellow. Is blue light harmful? Studies have shown that blue light can contribute to the risk of macular degeneration and cataracts. In a study published in the Transactions of the American Ophthalmological Society, a correlation between more exposure to blue light and an increased risk of developing macular degeneration was demonstrated. Since blue light exposure suppresses melatonin production, using electronics right before bed have been tied to sleep disorders according to multiple studies including the following: Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression. Such studies have led to an increase in the use of blue light blocking filters. I personally use blue light filters and I always recommend them to my patients, friends and family. Sources of Blue light: The SunLED/ fluorescent lightsTV (usually less than a computer, since we sit farther away)computer/tabletCellular phones Blue light from screens is minimal compared to what we get from the sun; however, due to the proximity and the amount of time spent in front of screens the blue light becomes a concern as far as ocular health. Blue light filters I am definitely a proponent of blue light filters. I use glasses to block the blue light from my work computer screen, but you can also download blue light filters such as www.justgetflux.com. Most blue light filters block between 10.6% to 23.6% of blue light, which can protect your eye while still giving you most of the benefits of blue light during the day. Your Optometrist may recommend blue light filtering glasses if you spend several hours of screen time, especially 2 hours before bed or if you are at risk for developing macular degeneration. Most cell phones have blue light filters built-in, you just need to know how to turn them on. I use the blue light filter or Night-shift on my iPhone all waking hours, but you can set it to turn on in the evening if you prefer. How to activate the blue light filter on your cell phone: iPhone blue light filter (Night Shift) Settings>Display & Brightness> Night Shift>Scheduled>Custom Schedule>Turn on (at a certain time) Turn off (at a certain time) Android blue light filter (Night Light) Settings > Display > Night Light Blue light filters do cause the screen to have a yellowish hue. This may be detrimental for photographers or someone who needs to see a precise color. If you are unable to use blue light filters due to the color change of the screen then I would recommend discontinuing screen time 2 hours before bed. Now I realize that this is unrealistic for most people, but if you find yourself having trouble sleeping it might be a good thing to try. https://youtu.be/37Pdb90wKIM Conclusion Since blue light filters only block 10.6% to 23.6% of blue light, it can help protect the health of your eyes while still providing the benefits of blue light that improve mood and memory.