Blue light is a type of visible light that has a short wavelength and a high energy level. Blue light is emitted by the sun, but also by artificial sources, such as LED lights, computer screens, smartphones, and tablets. While some exposure to blue light is beneficial (particularly the blue light from the sun) for regulating the circadian rhythm and enhancing alertness, too much exposure to blue light can have negative health effects, especially at night. Here are some of the harmful effects of blue light on your health:

• • It can disrupt your sleep quality and quantity. Blue light can suppress the production of melatonin, a hormone that regulates the sleep-wake cycle. Melatonin helps you fall asleep faster and stay asleep longer. When you are exposed to blue light at night, your melatonin levels are reduced, and your circadian rhythm is disturbed. This can lead to insomnia, daytime sleepiness, and impaired cognitive function [1].

• • It can damage your eyes and vision. Blue light can penetrate the retina, the inner layer of the eye that converts light into signals for the brain. Blue light can cause oxidative stress and inflammation in the retina, and increase the risk of macular degeneration, a leading cause of vision loss [1]. 

• • Blue light can cause eye strain, dryness, irritation, and headaches, especially when you use digital devices for long periods of time.

• • It can affect your mood and mental health. Blue light can influence the levels of serotonin and dopamine, neurotransmitters that are involved in mood regulation, motivation, and reward. Blue light can increase the levels of these neurotransmitters during the day, which can improve your mood and energy. However, blue light can also decrease the levels of these neurotransmitters at night, which can cause depression, anxiety, and addiction [2].

Therefore, blue light can have negative health effects on your sleep, eyes, and mood, if you are exposed to it excessively or at inappropriate times. To protect yourself from the harmful effects of blue light, you can follow these tips:

• • Avoid using digital devices at least two hours before bedtime, or use blue light blocking glasses or apps that filter out blue light. We prefer our clients to use blue blockers as soon as the sun goes down if you are on any blue light devices, like TV or cell phones.
    • • There are lots of ‘nicer’ looking blue light blocking glasses options these days, but we still use this style. These provide the best protection from blue light entering your eyes. However, if you plan on using these at work or outside your home, you may want another style.

• • Use dim red or orange lights at night, as they have the least effect on melatonin and circadian rhythm.

• • Get enough natural sunlight during the day, especially in the morning, to help synchronize your circadian rhythm and boost your mood.

• • Take breaks from using digital devices every 20 minutes, and look at something 20 feet away for 20 seconds, to reduce eye strain and fatigue.

By following these tips, you can reduce your exposure to blue light and improve your health and well-being.

Sources:
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734149/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5299389/