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March 4, 2015

Blue Light Exposure and Eye Strain – Are you at risk?

Every day we find not only ourselves but our children spending longer hours in front of a digital device. In fact, according to a 2012 survey conducted by The Vision Council, more than 1/3 of adults spend 4-6 hours a day with digital media or related electronic devices. In fact, 14% of young adults spend 10-12 hours per day. According to the American Pediatric Association, children are learning from their parents habits and spending an average of seven hours a day on entertainment media, including televisions, computers/laptops/tablets, smartphones, gaming devices, and other electronic devices. 

As an Optometrist, I receive frequent patient complaints of eyestrain and fatigue when using a digital device. Digital eyestrain is the result of overuse of digital devices and is the most common computer-related repetitive strain injury. When using a digital device for reading or close range use, eyes must constantly refocus and reposition to process what is being seen. After 2 hours of use, an individual may experience eye fatigue, blurred vision, irritation, headaches, and neck and back pain. 70% of adults experience digital eyestrain when using their electronic devices. Anyone in front of a digital screen is at risk, regardless of age, occupation or lifestyle and children are no exclusion.

Spending longer hours on a digital device also means our eyes have increased exposure to blue light. Blue light has a short wavelength and provides basic illumination to our world but long term exposure can have harmful effects on the eyes. Many devices are now made with LED lighting that releases a form of bright blue light. When blue light hits the lens it refracts and causes other objects in the surrounding to go in and out of focus.  Individuals often compensate by squinting resulting in eye fatigue.  

Our eyes absorb the blue light through the lens and retina.  Over exposure of blue light can cause symptoms of eyestrain, fatigue, headaches and trouble sleeping. More severely, long term exposure can lead to cataracts and age related macular degeneration (AMD). For those who are at risk for AMD or who have had cataract surgery must always take precautions against both UV and blue light. Additional evidence is accumulating indicating that blue light is also toxic to the human retina. Ophthalmologists, Braunstein and Sparrow found that blue light exposure led to cell death of cultured human pigment epithelial cells, while placing a blue blocking filter over the cells, protected them. Furthermore, they found that only blue light caused cell damage.

There is also a link between blue light and melatonin. Melatonin is a hormone which helps control sleep and wake cycles. Chronic exposure to blue light at night can reduce melatonin which disrupts our sleeping pattern.  In another study of blue light, researchers at the University of Toronto compared the melatonin levels of people exposed to bright indoor light who were wearing blue-light–blocking goggles to those exposed to regular dim light without wearing goggles. The fact that the levels of the hormone were about the same in the two groups strengthens the hypothesis that blue light is a potent suppressor of melatonin.

In practice, I often see children come in for eye examinations complaining of excess blinking, redness, tearing and blurred vision. Many of these symptoms are related to overuse of the computer and should be monitored and recorded. If you or your child is experiencing digital eyestrain or are concerned about your exposure to blue light come in and see your Optometrist. It is important to log how many hours per day you spend on a digital device, how far is the digital device placed from your eyes, and keeping a list of specific symptoms you or your child may be experiencing. Your Optometrist will use this information to determine the best treatment option for you or your child.

Treatment options can include glasses to be worn when using a digital device. Computer lenses and coatings can be created for making the use of digital devices more comfortable for the eyes by reducing the glare, improving contrast and relaxing the eye muscles. There are specific lens materials that can absorb up to 20% of blue light waves, and anti-reflective coatings that absorb an additional 10% of blue light waves. 

The proximity and position of the digital device is important. Computer screens and televisions should be placed in front of or just below eye level so the viewing angle does not exceed 35 degrees. When sitting at a desk, position the monitor or laptop at about an arm’s length away from the eyes which can reduce squinting. In a 2011 study by the State University of New York College of Optometry found people hold mobile phones 2 to 9 inches closer to their eyes than printed material causing more eye irritation, strain and pain. 

It’s really important for children to have a balance between playing on the computer, getting enough sleep, eating a well-balanced diet, and playing outdoors or being involved with extracurricular activities. Studies have shown that children who spend 2 hours or more on the computer are more likely to experience eye strain or fatigue which can increase their near sightedness.  In order to prevent eye strain, children should take frequent breaks from the computer. Every 20 minutes your child should take their eyes off the computer and look at an object at least 20 feet away for a minimum of 20 seconds. It’s a great habit to adopt for anyone who spends time on the computer.

The Canadian Pediatric Society discourages screen-based activities for children under the age of 2. Limit television watching to less than 1 to 2 hours per day for children over the age of 2 years. Avoid making television watching part of your regular daily routine. Often I see parents relying on a digital device to keep child occupied rather than finding more engaging activities or ones they can work on together. I encourage a balance between digital time, play time and family to keep your child well rounded.

For a more restful sleep at night, avoid looking at bright screens beginning two to three hours before bed for a more restful sleep. Keep televisions, computers and gaming devices out of your child’s bedroom and place them in common areas where you can watch your children while they use them. Late-night chatting online, surfing and texting with friends should not cut into important sleep time. Hence, it is important to set time limits for children when using any digital or gaming device to prevent over use and exposure to blue light and digital eyestrain.

Biography: Dr. Farrah Sunderji, OD completed her Optometry degree from the New England College of Optometry followed by a residency in Pediatrics and Vision Therapy at the Southern California College of Optometry.  Her practice Eyedeology is located in the Centennial Clinic. Unit 245, 520 3rd avenue SW Calgary, AB T2P0R3. For more information on children’s vision, check out her website at

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