Screens and eyes: Should you be protecting yourself?

Key takeaways:

• Reading on a screen poses unique challenges to our visual system
• Digital eye strain (or computer vision syndrome) is a group of eye and vision problems resulting from prolonged computer or digital device use
• 65% of American report experiencing symptoms of digital eye strain
• High-energy blue light can cause oxidative stress in the eyes and cause sleep disturbances. However, the impact of blue light emitted from digital devices is yet unclear.
• There are ways to reduce digital eye strain and blue light exposure. 

Related products:

• Vision: Contains lutein, zeaxanthin, and meso-zeaxanthin in a formulation that’s clinically proven to increase macular pigment optical density to help filter blue light, provide antioxidant protection, improve contrast sensitivity, and reduce glare. Vision also contains astaxanthin, which is clinically proven to help maintain focus adjustment and hand-eye coordination after extensive computer use.

It’s nearly impossible to lead a screen-free life these days—the average American spends an impressive 7 hours per day in front of a screen. 

Reading on a computer screen is different from reading print. The screen acts like a large flashlight shining in your eyes. Scrolling also causes our eyes to constantly flit across the screen. Approximately 65% of Americans report experiencing symptoms of digital eye strain. 

So what are the risks, exactly?

Here are a handful of conditions that excessive screen use can trigger, plus what you may be able to do about them.

Digital eye strain (or computer vision syndrome)

A blanket term used to describe the panoply of symptoms that result from looking at a screen, usually at arm’s length or closer [1]. Signs of digital eye strain (DES) include dry eyes, eye fatigue, and blurred vision, as well as extraocular symptoms like headache, and neck or shoulder pain, and back pain. Extended computer use can even impact hand-eye coordination. Eye-related symptoms can be classified into two categories:

Surface-related symptoms: 

One of the most common symptoms of DES is dry eye, which can be accompanied by irritation, redness, and burning. These surface-related symptoms result from quite literally forgetting to blink—our blink rate drops from ~18 times a minute to ~four times per minute when staring at a screen. 

Blinking hydrates and refreshes the eyes and provides a thin protective layer of tears which creates a smooth surface across the cornea and helps sharpen your vision. Without blinking, holes in the layer of tears appear, resulting in irregularity to the corneal surface which can contribute to blurry vision and discomfort. We also open our eyes wider when reading online, which makes the tears evaporate even faster.

Focus-related symptoms: 

When we focus on something up close, like a computer screen or a cellphone, the muscles surrounding the lens in the eye (called ciliary muscles) contract to increase the curvature of the lens. The ability to change the shape of the lens and focus is called “accommodation.” If we are focusing on a nearby object for a prolonged period of time, the muscles don’t have a chance to relax, leading to eye fatigue. This can exhaust your eyes’ ability to focus, resulting in blurred near or distance vision, difficulty refocusing from one distance to another, or even diplopia (double vision). Extended screen use can even lead to impaired hand-eye coordination, which relies on efficient eye accommodation [2].

Figure: The eye accommodates for close vision by tightening or contracting the ciliary muscles, allowing the lens to become more rounded, which increases its refractive power. When the eye is relaxed, the lens flattens, providing maximal focal length for distant viewing. 

Additionally, poor screen contrast (such as light gray text on a gray background) makes details difficult to distinguish, causing eyes to strain harder. High contrast, on the other hand, can cause glare, particularly in low-light conditions like a darkened bedroom. 

The good news? Digital eye strain can be treated with some lifestyle changes 

• Increase font size to help keep eyes from straining
• Adjust the screen setting so that the brightness is similar to the ambient lighting
• To reduce glare, use a matte screen filter on screens and use soft lighting
• Try to keep your chair around two feet from a computer screen
• The center of your monitor is best positioned 4-8 inches lower than eye level
• Artificial tears can help with lubrication if you find yourself with dry eyes
• Update—or obtain—an eyeglass prescription if you’re noticing frequent headaches
• Take regular breaks if you can, to help relax your eye muscles and reduce strain. Try the “20-20-20 rule”: Every 20 minutes, look away from the screen and focus your gaze at something that’s 20 feet away for 20 seconds.
• Consider supplementing with macular carotenoids. Lutein, meso-zeaxanthin, and zeaxanthin are yellow/orange plant carotenoids that naturally accumulate in the macula of the eye where they function to filter blue light, improve contrast sensitivity, and reduce glare [3]. They are also antioxidants, neutralizing free radicals and protecting the eye from oxidative stress. 
• Consider supplementing with astaxanthin. Astaxanthin is a red carotenoid found in microalgae and yeast. Supplementation with astaxanthin has been shown to increase blood flow to the retina to provide oxygen and nutrients [4] and restore accommodative function (focus adjustment) and hand-eye coordination after extensive computer use [5,2].

An FYI on types of screens–television screens generally pose little risk, unless you’re in the habit of sitting right up next to them. 

Let’s talk about blue light exposure

Blue light has emerged as a popular topic and has been more often than not maligned in relation to its presence in screens. Since we spend about 90% of our time indoors, often illuminated by or in the presence of screens, the concern is understandable. 

Blue light is on the end of the visible light spectrum that has a short wavelength (400-520 nanometers, or nm), meaning it’s also high energy. This high-energy form of light can cause cellular damage and oxidative stress. Unlike ultraviolet (UV) light, which has an even shorter wavelength (290-320 nm for UVB and 320-400 nm for UVA), and is largely absorbed by the cornea and lens, blue light reaches the retina, the light sensing membrane lining the back of our eyes. 

Luckily, the American Academy of Ophthalmology says that screens emit minimal blue light and that it poses no greater risk than the sun does. And, our eyes have a specialized structure called the macula, which forms the central portion of the retina, to block blue light. The macula contains high concentrations of three carotenoids, lutein, zeaxanthin, and meso-zeaxanthin, which function to absorb and optically filter blue light, provide antioxidant protection, and support visual performance.

While there is currently no evidence suggesting that digital light sources in normal use are toxic to the human eye, questions remain regarding the long-term cumulative exposure of blue light. Furthermore, as we age, levels of the protective carotenoids in our macula (also known as macular pigments) decline, by as much as 10% each decade [6], contributing to reduced protection from blue light (regardless of source), decreased eye health, and visual performance. 

Blue light has also been proposed to play a role in interrupting sleep patterns  

Phone use in and immediately before bed (not that we ever dream of bringing our phones into the bedroom!) is associated with poor sleep quality. Exposure to artificial blue light such as those emitted by phones and tablets has been shown experimentally to suppress melatonin and phase-shift the circadian clock. The extent of its impact, however, remains unclear [7]. We do know that late night technology-related behaviors, such as gaming, computer or phone use, increase brain alertness and delay sleep, and thus, plays a significant role. As we noted above, however, levels of our macular pigments (the natural blue-light blocking pigments in our eyes) decline with age and it remains to be determined whether the association between blue-light exposure and sleep changes with age.  

Combatting the effects of blue light exposure is manageable with some precautions. Here’s a short roundup: 

• Support a healthy macula (your natural blue light filter) by eating a diet rich in lutein and zeaxanthin (found in green leafy vegetables) such as the Mediterranean diet. Meso-zeaxanthin, the third macular pigment is rarely found in the human diet. Consider supplements like Elysium’s Vision that provide all three carotenoids.
• Wear sunglasses when in direct sunlight—this will help shield eyes from UV and some blue light, both of which are part of sunlight. Not all UV-blocking sunglasses are effective at blocking blue light so make sure to check the specifications. In general, yellow/amber/brown tinted glasses are more effective at blocking blue light.
• Consider using designated glasses and screens designed to filter out blue light when on devices.
• Choose warm lighting at home to reduce blue-light exposure. 
• Night mode is a great setting for nighttime device use to help reduce blue light exposure.

References

1. Kaur K, Gurnani B, Nayak S, et al. Ophthalmol Ther. 2022;11(5):1655-1680. Link
2. Yoshida K, Sakai O, Honda T, et al. Nutrients. 2023;15(6):1459. Link
3. Loughman J, Nolan JM, Howard AN, et al., Invest Ophthalmol Vis Sci. 2012;53(12):7871-7880. Link
4. Yasunori N, Miharu M, Jiro T, et al., J Clin Ther and Med. 2005;21(5). Link
5. Nagaki, Y., Hayasaka, S., Yamada, et al., J Trad Med. 2002;19:170-173. Link
6. Obana A, Gohto Y, Tanito M, et al. Graefes Arch Clin Exp Ophthalmol. 2014;252(8):1221-1228. Link
7. Foster R. Lighting Research & Technology. 2021;53(5):377-393. Link