Is Blue Light Bad for Your Eyes?

What Is Blue Light?

The light your eyes can see is called the visible light spectrum. The colors of the visible light spectrum are red, orange, yellow, green, blue, indigo and violet.

Each color on the spectrum has a different wavelength and energy level. Red, orange, and yellow light have longer wavelengths and contain less energy. Blue light has a wavelength within the 380 to 500 nanometer range. Blue-violet light has the shortest wavelength and highest energy of all the colors of visible light. About one-third of all visible light is considered blue light.

Blue light is often divided into two categories:

• High energy blue-violet light in the 415 to 455 nm range on the visible light spectrum is considered to be in the potentially harmful range.
• Blue-turquoise light in the 455 to 495 nm range helps regulate sleep/wake cycles.

Although some blue light studies have found an effect on the retinal tissue, these studies were performed on animals or on tissue in a lab, not on live human eyes. Plus, blue light from digital screens was not used. Due to this, the impact of prolonged exposure to digital blue light remains unclear, according to the American Association of Ophthalmologists.

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Sources of Blue Light

IMost blue light comes from the sun. Other sources include:

• Fluorescent lights
• LED (light-emitting diodes) TVs
• Computer monitors
• Smart phones
• Tablet screens

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Effects of Blue Light on Your Eyes

The eyes don’t block most blue light. Almost all of the blue light you see passes through the front of the eye and reaches the retina, which converts light into signals the brain uses to create images.

Does this mean you need to worry about the effect of digital blue light on your eyes? Retinal specialists say no.

Digital devices, such as smart phones and computers, emit blue light, and one study found that the average American spends more than seven hours a day looking at a digital device. While this may seem like the type of long-term exposure that can be bad for your eye health, that’s not necessarily the case.

According to Harvard Health, the amount of blue-violet light that comes from electronic devices does not increase the risk of macular degeneration, won’t cause retinal damage and won’t harm any part of the eye.

One thing most researchers do agree on is that exposure to blue-turquoise light before bedtime can disrupt circadian rhythm. Circadian rhythm is how your body tells you when it’s time to sleep and to wake up.

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Benefits of Blue Light

Blue-turquoise light has a longer wavelength at 455 to 495 nm and has several benefits. Blue-turquoise light:

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• Regulates the body’s circadian rhythm
• Boosts alertness
• Helps memory and brain function
• Contributes to a good mood

Sunlight can be beneficial as well. It is important for the growth and development of children’s eyes and vision. In fact, several studies have found that teens and young adults who don’t get enough exposure to daylight could be more likely to develop myopia (nearsightedness).

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Is Blue Light Related to Digital Eye Strain?

If you spend hours a day staring at screens, you might notice your eyes feel tired, achy and/or dry, and your eyes may tear or sting. Although you may think this is the result of exposure to blue light, these actually are symptoms of digital eye strain, often caused by looking up close for a long time. You can experience the same type of eye strain doing close work, such as reading or writing, for long periods of time.

One reason you may experience these symptoms more often after looking at digital devices is because people blink less when using digital devices. We normally blink about 15 times in one minute. While looking at an electronic device, people only blink about five to seven times per minute. Blinking keeps the eyes’ surface moisturized. Less blinking can cause blurry vision, headaches, and neck and shoulder pain, which are all signs of eye strain. In addition, it is important to take visual breaks by looking into the distance about every 20 minutes.

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How to Reduce Your Exposure to Blue Light

It’s virtually impossible to avoid blue light altogether. This is because the main source of blue light (including blue-violet light) is sunlight, even indoors.

There some things you can do to reduce your exposure to blue light and keep your eyes comfortable:

• Wear sunglasses when you’re outside. Sunglasses filter some blue light and also protect your eyes from the sun’s damaging ultraviolet (UV) rays. You can also get contact lenses with UV protection. A darker orange tint is best at filtering a larger spectrum of blue light.
• WUse blue-light filters for your computer screen, smartphone and tablet.These filters enable you to see the screen clearly while filtering some blue-violet light from reaching your eyes.
• Follow the 20-20-20 rule.Every 20 minutes, look at something 20 feet away for 20 seconds.

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Are Blue Light Blocking Glasses Worth It?

You’ve probably heard about blue light filtering contact lenses and glasses. These eyeglasses are designed to increase your eye comfort while looking at electronic screens. However, there isn’t agreement about whether or not they’re worth it.

The American Academy of Ophthalmology (AAO) advises against blue light glasses. “Skip the glasses that claim to protect your eyes against blue light, because of a lack of evidence that they are effective. The Academy does not recommend any special blue light-blocking eyewear for computer use.”

Other studies support the AAO’s view, finding that there isn’t enough evidence to prove that blue light-filtering lenses protect the eyes or prevent eye strain.

If you’re concerned about your exposure to blue light or have any symptoms of eye strain, make an appointment with your eye doctor for an eye exam.