For various reasons, people are exposed to light while sleeping at night. This may be because they like having a night light on. Or streetlights enter through the bedroom window.
Sleeping with (some) light may seem to have no effect because you are asleep. But your eyes and brain unconsciously perceive the light. Even with eyelids closed, some light can still penetrate. Just close your eyes and move a hand right in front of your face. Do you notice when your hand is in front of your eyes?
Studies show that sleeping in the light has a negative impact on your health. The best thing for your well-being is to sleep a dark room.
Influence of light in the night
Melatonin
Melatonin is the sleep hormone, which when it rises at night, helps you get sleepy and fall asleep. The production of this hormone is strongly tied to light intensity and color. Bright and blue light, which is naturally more present in morning light, suppresses the production of melatonin. In the morning, this helps to wake up. Blue light is also present in LED lights and various devices, such as cell phones and television. Use of these artificial lights in the evening and night can lower melatonin production at those times, making falling asleep difficult or delay sleep onset.
Sleep Quality
There are many factors that can affect the quality of sleep. Nighttime light is one of them. This can come from light in the home, as we have seen above, but also from streetlights.
People who live in large cities that are lit at night with bright streetlights are more likely to report experiencing sleep problems, research suggests.
Although the study does not prove cause and effect, scientists assume that bright outdoor lighting during the night interferes with sleep quality. People who are heavily exposed to light at night were more likely to report dissatisfaction with the duration or quality of their sleep compared with people who live in regions with low light, the findings showed.
Heart Rate
Several cardiovascular parameters, such as heart rate and blood pressure, go down during sleep. If you sleep in a moderately lit room at night, your heart rate goes up. This is because light activates the autonomic nervous system and triggers action. Thus, this prevents the body from resting properly.
Insulin Resistance and Risk of Obesity
A large study found that sleeping with artificial light is a risk factor for weight gain and developing obesity. A follow-up study discovered what may explain why. In those who slept with lights on (100 lux), sleep quality was worse. Those individuals slept more superficial.
The next day, their bodies were less able to handle glucose. The cells could not absorb glucose as well to use for energy. Glucose levels in the blood are higher. To compensate, the body makes more insulin. This is called insulin resistance and is linked to several conditions, including obesity and diabetes.
Pitch Darkness for the Best Sleep
In general, it can be said that sleeping in as dark a room as possible is best. Complete darkness reduces disruptions to sleep the best and has a beneficial effect on health. To achieve this, turn off lights in the bedroom and close blackout curtains. An eye mask can also help, especially if your partner still wants to read in bed while you already want to sleep.
Nightlight?
Some people have difficulty sleeping in pitch darkness. For example, children who are anxious at night or for safety reasons. If you still want a light on at night, use one with warm, orange light. Make sure the light does not shine directly on your face and place the lamp close to the floor. For example, you can place a salt lamp on the landing. This light is most appropriate at night.
Light therapy
In addition to darkness at night, adequate light in (the beginning of) the day is important for a good night's sleep. Do this by exposing yourself to bright light as soon as possible after waking up. Turn on the lights, open the curtains, go outside if you can. Do you get up before sunrise? Then consider light therapy.
The AYOlite light therapy glasses are on sale now at Word and Well-being. Interested? Click below to go to the webshop.
Questions about light therapy can be asked by emailing info@woordenwelzijn.nl. I am happy to help.
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