Why Blue Light is Bad for Us

Limiting Blue Light

Light is made up of electromagnetic energy waves. For the most part, people understand that the sun emits both visible and invisible light rays. Some the human eye can see in the form of color, such as red, yellow, blue, and green, and some that cannot, such as ultraviolet light rays that tan or burn the skin. What is not as commonly understood is that different colored light rays emit varying degrees of energy. It is this energy that travels in waves.

Each wavelength, depending on its length and strength, registers a different color. All of the many colors make up the electromagnetic spectrum. The entire spectrum is seen as white light or sunlight. The shorter the wavelength, the higher the energy. Blue light has one of the shortest and highest wavelengths making it more energetically powerful than other colors.

Blue light naturally comes from the sun. It is what makes the clear sky look blue. Since all shades of blue, such as Purple, Indigo, and Turquoise, are included in the blue light spectrum, about one-third of all light is considered “Blue”. However, blue light also comes from artificial light, fluorescent and LED lighting, and any electronic devices with a screen, such as computers, laptops, tablets, and cell phones, making blue light a concern. People spend far too much time staring at digital screens emitting blue light. It is estimated that over 50% of all people spend at least six hours each day staring at a digital display.

Because blue light wavelengths are short, they flicker easily. This flickering can cause eyestrain, headaches, blurred vision, and fatigue due to reduced visual contrast, sharpness, and clarity. Furthermore, too much blue light exposure before bedtime can disturb one’s circadian rhythm and cause sleep problems. This can lead to health problems, such as depression, diabetes, and obesity.

The human eye isn’t able to block blue light from reaching the back of the eye as it does other forms of light, such as ultraviolet light. Not even sunglasses can protect the eye from blue light passing through the cornea and lens and reaching the retina (the very back of the eye).

There are some benefits to blue light exposure. For example, exposure to blue light during the day from the sun actually helps to regulate one’s circadian rhythm, the natural wakefulness and sleep cycle. Light therapy is used to treat Seasonal Affective Disorder (SAD) during darker and colder months of fall and winter. Additionally, exposure to artificial blue boosts memory, recall, alertness, and overall cognitive function, which tends to elevate mood.

Too much exposure to blue light can cause long-term damage to the eyes, specifically the retina, which contributes to a condition that is similar to macular degeneration. Macular degenerative is a condition that affects the central part of the retina (the Macula), which results in a distortion in eyesight or a loss of central vision. It often leads to loss of vision and even blindness. This condition is typically seen in older adults and the aged due to normal wear and tear. However, damage to the retina is now being seen more frequently in younger people due to excessive exposure to blue light. Digital devices are now considered to increase a person’s risk of macular degeneration at a lesser age than deemed normal. So, what is one to do to protect one’s eyes from the negative effects of blue light?

The side effects of too much exposure to blue light related to the prolonged use of electronic devices can be combated by wearing digital protection lenses. These lenses are often in the shade of yellow to counteract shades of blue. In essence, they filter the blue light and help to reduce glare from digital screens and other forms of artificial light. Blue light filters made out of thin tempered glass are also available for cell phones by a variety of companies, such as RetinaShield made by Tech Armor and Eyesafe by Health-E. Taking regular breaks from screens is also helpful.

And, finally, if one is having eye surgery for cataracts, it may be a good idea to ask how much blue light protection one’s new intraocular lens (IOL) will provide. This new lens replaces the cloudy natural one. Some lenses are better than others for blocking blue light. If nothing else, eyeglasses with blue light filters are a healthy option after surgery, especially when one plans on sitting long hours in front of the computer screen.

Sources:

AllAboutVison.com – https://www.allaboutvision.com/cvs/blue-light.htm

Harvard Health Publishing – https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side

BlueLightExposed.com – http://www.bluelightexposed.com/