Since the beginning of mankind, the sun has been and still is our major source of light. It did not take long for people to start wondering how exposure to sunlight affects our skin. As a result of their curiosity, we now know that wearing sunscreen is important to prevent damage from UV (ultraviolet) radiation to our skin when we spend long amounts of time in the sun. However, with today’s amount of technology, it seems that we have another type of light to be wary of – blue light. The most common sources of blue light are electronic devices such as computers, tablets, and phones. The increased exposure to blue light certainly raises some questions about its possible effects on our skin.
Light is composed of electromagnetic particles that move in waves. These waves have different lengths which determine the type of light that we see (or do not see). Blue light has a wavelength of 400-495 nanometers, which is found in the range of light visible to the human eye known as the visible spectrum. In addition to wavelength, another important property of light is the amount of energy it gives off. Interestingly, the amount of energy that light emits is inversely related to its wavelength. This means that the shorter the wavelength, the higher the amount of energy is given off by the light and vice versa. Blue light has a wavelength on the shorter end of the visible spectrum, so according to the inverse relationship, it emits a fair amount of energy which may have biological effects on the skin.
Blue Light Effects on Skin Aging
Blue light effects on facial aging are becoming a concern because the energy from blue light gets absorbed into the skin, which then causes chemical changes in the skin cells. Some of these changes can be beneficial. For example, the short-term use of blue light in dermatological practice is under research for conditions such as psoriasis and acne. On the other hand, long-term exposure to blue light could potentially be dangerous. Blue light may indirectly cause damage to cells and can also decrease antioxidants that protect our skin from damage. The resulting cell damage and decreased protective properties might increase the risk for premature aging of the skin.
Blue Light from Devices
In one study, researchers found significant damage to the skin from blue light. They applied one dose a day of about 30 joules (a measure of energy) per centimeter squared of blue light to skin cells over a three-day period. The average person will not have the tools to measure the output of blue light from their devices. Luckily, a website called f.luxometer has this information.
Here is the blue light output for a few devices:
1-hour dose: 0.0225 J/cm²
12-hour dose: 0.271 J/cm²
MacBook Air 2011
1-hour dose: 0.0200 J/cm²
12-hour dose: 0.240 J/cm²
1-hour dose: 0.0365 J/cm²
12-hour dose: 0.438 J/cm²
The amount of blue light from electronic devices is clearly not as strong as the 30 J/cm² doses used in the studies. To put this in perspective, it would require approximately 2 weeks of constant exposure to blue light from devices to reach the same doses in the studies. Even though the damage may be much slower, the risks are still possible in those that constantly use their devices. More and more people are recognizing these risks and have developed ways to protect ourselves from blue light exposure including the use of special glasses and installation of the blue light reducing apps.