Do you have trouble falling asleep at night? If so, your digital devices might be to blame. Artificial blue light, most commonly emitted from sources, such as device screens and energy-saving bulbs, can have damaging health effects on your eyes and may impact sleep quality. (29)
What is blue light?
Blue light, emitted by both the sun and artificial light sources, is a defined range of light from 415 to 455 nanometers (nm) on the visible light spectrum. (29) This type of light is a short wavelength, meaning it produces greater amounts of energy compared to other visible light. If you’ve ever wondered why the sky is blue, it’s a result of the shorter wavelengths of blue light that easily scatter light in the earth’s atmosphere as they collide with air and water molecules. (6)
Sources of blue light
Industrialization and modern life have resulted in significant changes in the way we live. In developed countries, natural sunlight exposure has become less frequent, and exposure to artificial light has increased. (5) Artificial blue light is all around us, from the light bulbs we use to brighten our homes, to the smartphones we use to stay connected.
Sources of artificial blue light include:
- Digital screens (e.g., computers, smartphones, tablets, and televisions)
- Light-emitting diodes (LED) (28)
Did you know? Two-thirds of adults aged 30-49 and 37% of adults aged 60 and over, spend at least five hours per day on digital devices. (27)
Negative effects of blue light exposure
While artificial light has proven to be useful in our modern daily lives, excessive exposure poses some health risks.
May cause eye damage
It has been suggested that chronic (long-term) blue light exposure may increase your risk of developing several eye conditions. (29)
Blue light can damage eyes when light passes through the cornea and lens and reaches the retina. The lens protects the retina by absorbing blue light; however, this protective effect may theoretically result in the formation of cataracts. Cataracts are characterized by cloudy, discolored lenses and may lead to total blindness over time. (29)
Furthermore, staring at blue light-emitting screens may cause you to blink less often, which can lead to eye strain and eye dryness. (19)(24) Regular blinking is necessary for normal tear distribution and to protect the eye surface. (2)
One of the biggest concerns related to blue light exposure is the risk for oxidative damage to the retina and potential increased risk of macular degeneration, which is the leading cause of vision loss in North America. However, there is no research in humans to confirm this link. (29)
Did you know? Most people blink an average of 15 times a minute, but when on screens, only 3-4 times a minute.
Impacts sleep quality
There are numerous studies linking blue light exposure to sleep issues, such as difficulty both falling and staying asleep.
Nighttime exposure to blue light can impact blood pressure and body temperature regulation by disrupting the circadian rhythm. (15) The circadian rhythm is your body’s internal clock, which regulates your sleep-wake cycle.
When the sun sets, the retina in your eye detects the shift from light to dark; this signals the pineal gland in the brain to produce melatonin, a hormone responsible for regulating your sleep-wake cycle. As melatonin levels in the blood increase, mental alertness decreases, and you begin to feel sleepy. Once the sun rises and you are exposed to natural blue light, melatonin production slows down, heightening mental alertness. (16)(12) When melatonin production is altered by inappropriate light exposure, the circadian rhythm is disrupted. (7)
Exposure to blue light sources during evening hours stimulates the brain and interferes with the body’s natural response to secrete melatonin. Without sufficient melatonin levels, the circadian rhythm is disrupted, affecting sleep quality, and makes it difficult to fall asleep. (29) If you have trouble falling asleep, supplementing with melatonin may help. (12) Talk to your healthcare practitioner who can help determine if supplementation is right for you.
May accelerate skin aging
Some research suggests that blue light may harm skin by contributing to skin cell damage and aging. Exposure to light from electronic devices promotes oxidative damage in skin cells, further accelerating skin aging. (10)(5) Studies have also shown that blue light may cause more skin pigmentation than ultraviolet light (UV) from the sun. (14)
Are there any benefits of blue light?
Blue light does offer some health benefits; however, timing is key. Daytime blue light exposure increases alertness and helps regulate the circadian rhythm. Research suggests that blue light may improve memory and cognitive function. (9)(4) Daytime blue light from natural and artificial sources may also have mood-boosting effects. (11)
Blue light therapy has shown effectiveness in relieving symptoms associated with some conditions, including:
- Jet lag
- Mild to moderate acne
- Neonatal jaundice
- Premenstrual syndrome (PMS)
- Seasonal affective disorder (SAD) (13)(18)
Reducing the negative effects of blue light exposure
Outlined below are some practical solutions to reduce exposure to artificial blue light and mitigate some of its harmful effects.
Increase macular carotenoid intake
Lutein, zeaxanthin, and meso-zeaxanthin are types of carotenoids that have antioxidant properties. These three carotenoid pigments accumulate in the eyes within the lens and central retina, known as the macula, and absorb blue light. (29) The accumulation of lutein, zeaxanthin, and meso-zeaxanthin helps protect your eyes from oxidative damage caused by free radicals. (25)
As we age, conditions affecting the eyes, such as macular degeneration and cataracts, are more common. Diets rich in lutein and zeaxanthin can slow or prevent the progression of age-related eye disorders. Lutein and zeaxanthin are found in many green, yellow, and orange-colored foods, such as kale, spinach, orange peppers, corn, and egg yolks. (1) Though the recommended daily intake of lutein is 6-20 mg/day and of zeaxanthin is 2-4 mg/day, most people on western diets are deficient based on dietary intake, and get only 1-2 mg of lutein and less than 1 mg of zeaxanthin daily. (1) Unfortunately the third macular carotenoid, meso-zeaxanthin, which is the most powerful of the three in terms of its antioxidant properties, is not readily found in most foods.
Therefore, supplementation with lutein, zeaxanthin, and meso-zeaxanthin is important for protecting against oxidative damage to the eyes. Studies have shown that supplementation is effective in restoring antioxidant levels in the eyes and protecting against digital eye strain and blue light. (3)(23) Speak to your integrative healthcare practitioner for specific guidance and recommendations.
Wear blue light-reducing glasses
Blue light-reducing glasses, available with clear or amber-colored lenses, are a safe and effective tool for reducing blue light exposure. They partially filter short-wavelength light without significantly impairing vision. (22)
One study investigated the effects of amber-colored lenses and found that wearing blue light-reducing glasses with amber lenses for the two hours leading up to bedtime significantly improved sleep quality and total sleep time. (26) Another study tested the effects of blue light-reducing glasses on adolescents who use LED screens for several hours a day. Individuals who wore blue light-reducing glasses had higher levels of melatonin and were able to fall asleep faster. (21)
Minimize screen time after sunset
When possible, avoid using digital devices once the sun goes down. To optimize sleep, remove any blue light-emitting sources from your bedroom, particularly computers, televisions, and smartphones. Research suggests that eliminating or reducing blue light exposure with blue light-reducing glasses, for three hours before bed, is ideal for optimal sleep. (8) Start by avoiding screens 30 minutes before bed and gradually increase the amount of time away from screens. (17)
Enable blue light filters on your devices
Many computers, smartphones, and tablets offer settings that allow you to adjust the color warmth of the device’s screen. These filters reduce the amount of blue light emitted from the screen. One study found that light-blocking software for digital screens improved sleep quality and cognitive function in night shift workers. (20)
Check the settings on your devices and consider opting for automatic screen adjustments, which alter the screen warmth according to the time of day. These settings are synced with your time zone to mirror the natural blue light cycle of the rising and setting sun. If your computer, phone, or tablet doesn’t have a blue light filter setting, there are several downloadable apps to help reduce blue light.
The bottom line
Chronic blue light exposure can have lasting negative impacts on health, particularly affecting sleep quality and eye health. Negative effects can be mitigated by minimizing screen time, using blue light filters, eating a diet rich in carotenoids, and daily supplementation with lutein, zeaxanthin, and meso-zeaxanthin when directed by your integrative healthcare provider. Do your best to minimize the use of artificial blue light-emitting devices, especially during evening hours.
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