Blue light has both natural and artificial sources. While blue light has its benefits, it also presents health risks—particularly to your vision. Prevent Blindness, the nation’s oldest volunteer eye health and safety organization, explains what blue light is, how it affects you, and what you can do to reduce the risk of eye damage.*

What is blue light?

Blue light is part of the light spectrum. All the colors of the spectrum (red, orange, yellow, green, blue, indigo, and violet) are perceived as wavelengths, and they contain different amounts of energy. Blue light rays contain more energy than those closer to the red end of the spectrum.

What are some benefits of blue light?

All colors contained in light have benefits.

Some benefits of blue light include:

• Increasing alertness
• Boosting memory and cognition
• Elevating mood
• Regulating the body’s natural sleep-wake cycle (circadian rhythm)
• Aiding eye development and vision in children

Moreover, there is evidence that too little blue light may contribute to nearsightedness.

What are some sources of blue light?

Sunlight is the main blue light source. 

Other sources include:

• Fluorescent and compact fluorescent light bulbs
• LED lights and flat-screen LED TVs
• Computer monitors, tablet screens, and smartphones

What are some drawbacks of too much blue light exposure?

Most visible blue light passes through the cornea and lens of the eye to the retina. 

Some studies suggest that too much exposure to blue light may:

• Prematurely age your eyes
• Cause eye strain, dry eyes, and eye fatigue through long-term exposure to digital screens
• Cause retinal damage, which can lead to macular degeneration
• Disrupt your body’s circadian rhythm

Evidence also indicates that children’s eyes may absorb more blue light than adults’ eyes.

How can I protect my eyes from overexposure to blue light?

Prevent Blindness recommends several steps you can take to protect your eyes from too much blue light. 

• Reduce your screen time. Give your eyes a rest by taking frequent breaks from phone and computer screens. One way is to use the “20-20-20 rule.” This means every 20 minutes, you need to focus on something at least 20 feet away for at least 20 seconds. 
• Use screen filters. Blue light filters can be purchased for phones, tablets, and computer screens. They won’t block all the blue light, but they will reduce the amount that can reach your retinas. 
• Use blue light-blocking computer glasses. You can order a pair of glasses with yellow-tinted, blue-light blocking lenses, which are helpful for long-term digital screen gazing. These lenses increase contrast and can help reduce eye strain. 
• Limit your screen time two to three hours before you go to bed.
• Consider eye lens replacement. After cataract removal, the surgeon can replace the cloudy lens with an intraocular lens (IOL) lens that naturally protects the eye from most ultraviolet (UV) light and some blue light. Certain types of IOLs can protect the retina specifically from blue light.
• Wear protective eyewear when you’re in the sun. Sunlight is the largest source of blue light waves—far outweighing staring at a computer screen all day.
• Use eye drops or fake tears to lubricate your eyes. We tend not to blink as much when screen-gazing, which can contribute to dry eyes, eye fatigue, and blurred vision.

In addition to too much blue light, overexposure to the sun’s ultraviolet rays can damage your eyes, as well. Studies suggest that too much UV light can increase your risk of cataracts, eye tumors, and cancer.

*Prevent Blindness. (n.d.) Blue Light and Your Eyes. https://preventblindness.org/blue-light-and-your-eyes/