Do you often feel sleepy or unproductive at work? Poor lighting in your office could be one of the culprits. Whether you have returned to your normal office setting or continue to work from home, it is important to think about the kind of lighting you are using in your office space.
In this Q & A, Mariana Figueiro, PhD, Professor in the Department of Population Health Science and Policy at the Icahn School of Medicine at Mount Sinai, and Director of the Light and Health Research Center at Mount Sinai, explains how light affects the brain and how exposure to daylight can improve your overall health and mood.
Could the light in my office be making me sleepy?
Yes, absolutely. An office that is too dark can make you feel like crawling back under your covers. That is because light has a profound impact on people.
First, it shifts the timing of your biological clock so that you are in synchrony with your watch. So, when you wake up and open your shades, the light that pours in helps your body confirm that it is seven in the morning and time to get ready for the day.
Second, light has a direct effect on the brain. Similar to a cup of coffee, light makes you more alert. Increasing the amount of light at any time of the day will make you perkier because of the cup-of-coffee effect of light.
During the daytime hours, if you are in a dark room or a low-light level room—like an office with no windows and inadequate lighting—you will tend to be sleepier. To counteract this, I recommend exposing yourself to bright light during the day to both maintain your body’s synchrony with your watch and for the cup-of-coffee effect of light which increases your alertness and makes you less sleepy.
What can I do to reduce fatigue caused by lighting?
While bright light is important during the day, you should avoid being in the direct view of the light source or the light bulb. This can cause eye strain or headaches. Northern exposures from windows will give you the most comfortable light because it provides an indirect light, or diffuse daylight, instead of direct sunlight. That bright, diffuse light is overall more comfortable.
So, to reduce fatigue, increase the amount of diffuse and ambient light and minimize direct pools of light or direct sunlight in the space.
I am a remote worker. What kind of light should I have in my home office?
During the daytime hours you want brighter amounts of light than what you probably have at home. We typically tend to have low-light levels at home, and that is appropriate for the evening hours. But during the daytime, when you’re working, I suggest adding two to four more table or floor lamps near you. This way you’re increasing the amount of ambient light and making your space brighter during the day.
If you can work near a window, specifically a northern exposure window that has daylight (not sunlight) coming in, that is the absolute best light source. It’s bright, it’s the right color, and it’s on at the right time. But if you can’t have daylight, for instance if you are working in a basement, I suggest you use table and floor lamps to brighten up your space.
How does exposure to daylight help regulate my circadian rhythm, or the sleep-wake cycle?
Daylight has a considerable amount of short wavelength or blue light, which is the light that we need to be synchronized with our biological clock. Also, we know that inadequate indoor lighting can make you feel sleepy and, daylight provides a lot of light. For example, on a bright sunny day you get about 50,000 to 100,000 lux [a standard measurement of the amount of light] of daylight, but indoors you probably get 200 to 300 lux reaching your eyes. So that gives you an idea of how much less light we’re getting indoors and how important it is to be exposed to daylight, not only to avoid dozing at work, but to keep your circadian rhythm in synch.
At the Light and Health Research Center, we just finished an interesting study related to this, using “smart” windows in a large building in Reston, Virginia. The smart windows that were installed in the building change the transmittance and the amount of light coming through the windows based on the heat and the sunlight hitting the window. For example, if there’s too much heat or sunlight coming in, the smart windows would reduce the transmittance of heat and light, making it cooler indoors and reducing sunlight coming into the space, which reduces eye strain or other discomfort. As a result, there is no need for window shades and the lights that come in are appropriate for stimulating your circadian system and keeping you alert.
For this study, we compared these “smart” windows to regular, untinted windows with shades. In just one week, we found that people who were exposed to the “smart” window slept better, had fewer feelings of anxiety and depression, and reported feeling more energetic. Daytime light will lead to better nighttime sleep. And when you sleep better, you simply feel better.
I have heard about blue light emitted by my electronic devices. Should I avoid blue light in the evening? Do blue light filters work?
Exposure to blue light is important to keep your circadian rhythm in sync, but too much of this light in the evening can disrupt sleep by suppressing the body’s production of the hormone melatonin. Triggered by darkness, the levels of melatonin in your body typically rise in the evening about a couple of hours prior to your normal bedtime— a signal to your body that it is time to sleep. While daylight is the largest source of blue light, it is also emitted, to a much lesser extent, by florescent lights, LED televisions (the newest sets), and cell phones, as well as computer and tablet screens.
Blue light filters work to a certain extent. We have done some work where we collected data with the iPad Night Shift, which automatically reduces blue light emissions in the evening, and we did see that there is a reduction in the impact on melatonin production, but it’s not perfect.
If you are looking at your cell phone for three hours before going to bed, even with a blue light filter, there will still be an effect on melatonin production. Albeit it’s going to be a smaller effect, but it’s not going to completely take away the problem. It’s better than nothing, so I do recommend using a blue light filter. More importantly, you should also dim down the screen, so that you get less light at your eyes.