Blue Light: What is it and Why Should I be Concerned?

By Stephen Cohen, O.D. Optometrist, Scottsdale

We are fortunate that, in spite of the pandemic, we can work remotely, and our children can learn remotely. However, this benefit does not come without consequences. For one thing, we are not “designed” to spend extended periods of time engaged in near vision activities (like staring at a computer screen). On top of that, many of us and many of our children spend leisure time on a smart phone or tablet. Additionally, when we spend time in these activities, we don’t blink as much (often half as often as usual), and it is the blinking process that allows us to coat our eyes with new tears.

There is another issue with device use: Blue light. Blue light is the wavelength of light that is on one end of the rainbow, and it is right next to ultraviolet light (UV). We know that UV can be damaging to our skin and to our eyes, and now have learned that blue light can penetrate deeply into the eyes and cumulatively over time, can contribute to the development of macular degeneration. It can also cause eyestrain, headaches and, since it can deplete melatonin, can impact our sleep cycle. We are now exposed to higher levels of blue light indoors, due to some of the new overhead lighting as well as from tablets, phones and computer monitors.

With the amount of screen time skyrocketing, there are a number of steps we can take to combat these issues. For one thing, we can periodically use artificial tears during the day. We should also follow the mantra of “20-20-20,” where every 20 minutes on a device, we take a 20 second break and look at something 20 feet away. This is akin to taking breaks between sets of weightlifting, where we can get some “recovery” before proceeding further. We should also periodically do blink exercises where we squeeze our eyelids tightly shut four to five times in a row. This promotes clearing out of the glands in our lids that produce the part of our tears that prevents them from evaporating too quickly. Lastly, protection from prolonged blue light exposure can be very helpful, especially for children. There are blue light glasses that can be purchased on line, but you first need to find out how much blue light blockage they have, and, while using these glasses can be beneficial, also keep in mind that these often have lower quality lenses that can actually distort vision and create eyestrain. Optically ground computer glasses can have custom eyestrain reducing prescriptions, and coatings that will block glare, almost 100 percent of UV, and up to 90 percent of blue light.

While “Don’t it Make My Brown Eyes Blue?” is a classic song, we don’t want blue light and prolonged device use to make our precious vision and eye health to be compromised. Now…give me 20-20-20!

Dr. Stephen Cohen has been in private practice in Scottsdale since 1985. His office motto is, “Where modern technology meets old-fashioned care,” and he provides eye care from infants to seniors.  He can be reached at 480.513.3937 or by email at  His website is


3-D Or Not 3-D

Click to read more about Dr. Cohen

By Stephen Cohen, O.D. – 

Technology changes so fast that what was new last year, can be passé today. While these mind-boggling advances occur at breakneck speeds, we can’t always anticipate the unintended consequences that come with the advances. Case in point is Carpal Tunnel Syndrome (surgery for which I am now recovering as I awkwardly attempt to type out this message), which has become an unanticipated consequence of prolonged, repetitive computer use. The recent explosion in 3-D technology is showing signs of being a similar example.

Many movies are now being released in 3-D as well as 2-D technology. What many don’t realize though, is that our ability to appreciate the 3-D effect is contingent upon our eyes ability to see the two images with equal clarity and positioning in order to merge them into one three-dimensional image.

A recent peer-reviewed study published in Optometry and Vision Science showed that for about 20 percent of study participants, 3-D images (movies, home TV, video games) can lead to blurred or double vision, dizziness, disorientation, motion sickness and nausea. Interestingly, younger study participants were more symptomatic than older study participants.

Here are some tips. If your child complains while watching a 3-D movie or while using a 3-D device, schedule an eye exam to see if there is an issue with how their eyes are working as a team. Such a problem can not only affect movie-going, but can create problems with reading and with sports. When you go to a 3-D movie, studies suggest that sitting in the center and/or closer to the screen can increase symptom, while sitting at an angle to the screen may help to decrease symptoms.

For the future, there is hope. Technology in 3-D filming, projecting and 3-D movie glasses is being developed to address this mismatch between how our eyes focus and how they work together as a team – the issue that appears to be the primary cause of these symptoms.

Until then, pay attention to your symptoms. If it’s an issue for you, try going “old school” for now and see the movie in 2-D. A good movie is a good movie in either form. Doing so can help relieve you of 3-D induced headaches, both in the wallet as well as above the shoulders.

Sports Vision

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By Stephen Cohen, O.D. – 

“Float like a butterfly. Sting like a bee. Your hands can’t hit what your eyes don’t see.”

Muhammad Ali’s words apply for all sports. Nothing happens until the eyes tell the brain to tell the muscles what to do. Most of us equate great vision with being able to see 20/20. Although this level of eyesight is the benchmark for visual performance, it is only one of several important factors and skills. Other significant skills include depth perception, visual reaction time, eye tracking and teaming and peripheral awareness. Each plays a vital role in not only seeing, but in judging position, movement, speed, action and response.

With athletic endeavors come injuries. It is estimated that about 100,000 sports-related eye injuries occur each year, with about one-third of these to children under the age of 16! In children’s hockey and baseball leagues that require protective eyewear, eye injuries drop by 90 percent! It is also imperative that, as parents, we make sure our children have UV protection while engaging in daytime outdoor sports. UV damage (e.g., cataracts) is cumulative, and may take decades to show up.

Vision correction options are numerous. Unlike glasses, contact lenses do not alter the perception of image size, can provide better peripheral vision and some contacts also have UV protection built in. There are new tinted contacts (often bright red or green) that enhance contrast and are being used by professional baseball players and golfers. For glasses wearers, there are lens materials that are 20 times stronger than regular lenses, and can withstand a ball traveling at 90 mph. Additionally, a polarized lens or a non-reflective coating can dramatically cut glare. Lastly, the glasses (e.g., bifocals) someone uses for normal activities may not be optimal for sports. Athletes spend a lot of time and money on specific equipment for sports, and then use a one size fits all approach to their eyewear. Sports glasses could make as significant difference in performance as other equipment.

Whether you’re a competitive athlete or a weekend warrior, thinking about your eyes and vision can help to take your game to the next level.

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