Computer Vision Syndrome:  What is it?

Computer vision syndrome, also known as CVS or digital eye strain, has become all too common in this digital age. Many of us are familiar with the effects of computer vision syndrome even if we are not aware of the condition by its name. CVS encompasses a wide range of eye strain symptoms caused by consistent work with a computer monitor or handheld electronic device. It’s a condition that results from focusing the eyes on a computer or other digital display (like a tablet, smart phone or monitor) for long periods of time uninterrupted. It’s a form of repetitive stress condition like carpal tunnel syndrome, but solely affecting the eye muscles and ocular tissues. According to the National Institute of Occupational Safety and Health, computer vision syndrome affects about 90% of people who spend three or more hours per day at a computer!

While we don’t know of any long-term damaging effects of computer vision syndrome, the short term effects can certainly be felt. Symptoms of computer vision syndrome include headaches, blurred vision, neck pain, ocular redness, eye strain, dry eye, dizziness and difficulty refocusing. The effects of staring at a computer for hours uninterrupted appear to be worse than those from reading a book or paper for the same amount of time, because computers also involve screen brightness, contrast, glare, flickering light, and blue light.

What is Blue Light?

Many eye care professionals are increasingly concerned with the effects of blue light. But what exactly is “blue light”?Blue light is a type of visible light, meaning it is electromagnetic radiation we can see. Approximately 1/3 of all visible light is considered high energy visible electromagnetic radiation (HEV), or “blue” light. Most blue light is produced by the sun, but digital screens (smart phones, computers, tablets, televisions) also emit blue light.

One of the issues with blue light is that our eyes don’t filter it. With damaging ultraviolet light, for example, our eyes filter out many of the harmful rays (only about 1% of ultraviolet light actually reaches our retina, yet can still be very damaging to ocular structures). On the other hand, 100% of blue light reaches our retina. This means we have no natural defense against any damage caused by constant and close exposure to blue light emitted from computer screens.

This increased exposure to blue light can contribute to eye strain symptoms related to computer vision syndrome. There is also evidence it contributes to photoreceptor damage (as does UV light) in the retina, known as macular degeneration.  This disease can lead to permanent vision loss. Another adverse affect of blue light is its disruption of the circadian rhythm. By being exposed to blue light shortly before we go to bed, such as browsing on our phones, our sleep patterns can be interrupted.  The blue light overstimulates us and interferes with us falling asleep.

Until the long term effects of blue light are studied more thoroughly, we can only be diligent in trying to protect our eyes while working on computers. Blue-blocking antiglare filters can be used in spectacle lenses to cut out this harmful light. Blue light is also that part of the visible spectrum that is most susceptible to atmospheric effects that contribute to glare. A filter in our spectacle lenses can simultaneously reduce disabling glare while blocking out harmful blue light.

Ergonomics: One Solution to Combat CVS

Ergonomics is a broad field of study in how to design a work environment to suit the comfort of  workers.  VDT ergonomics, or Visual Display Terminal ergonomics, is a specific type of ergonomic related to computers and display terminals. It addresses ways to prevent computer eye strain and postural discomfort by creating better work conditions while seated in front of a computer workstation.

There are a few things we can do at the office to adhere to good VDT ergonomics and reduce the prevalence of computer vision syndrome. First, make sure the lighting in our work area is not too dim or too bright. Second, glare on your computer screen needs to be reduced or eliminated. Glare and poor lighting both cause our eyes to overcompensate and strain in an attempt to see clearly. Keeping a clean screen is a great way to prevent this overcompensation as well.

The angle and distance of the screen relative to our eyes are important as well.  We should keep screens 20 to -25 inches (50 to 65 cm) from our eyes, with the centre of the screen at about chin level, so that our eyes are pointed in a direction slightly down from the straight-ahead gaze position. At this angle, you won’t be straining your neck up or down, and your eyes are working at a more natural and therefore comfortable angle to read the majority of text.

Along with VDT ergonomics, there are other simple solutions for preventing computer vision syndrome at the office.

Solutions for Computer Vision Syndrome

1. Eye drops

Using lubricating eye drops, also known as artificial tears, is a great way to alleviate some symptoms of computer vision syndrome.  If your eyes feel dry or gritty, burn or look red, moisturizing eye drops can provide immediate relief.

2. Blinking

This seems like a strange idea – aren’t we blinking all the time already?  The normal blink rate is between 15 to 20 times per minute. But while looking at a computer screen or phone, our blink rate drops to between 5 to 10 times per minute. We go on autopilot and just stare at the screen, read the text, and ‘forget’ to blink. Blinking helps restore the eyes natural tear film, if you don’t blink the eye gets irritated and vision can suffer as well. By making sure we consistently blink when working on a computer, we can help prevent dry eye caused by computer vision syndrome.

3. The 20-20 Rule

The 20-20 rule is great for alleviating computer vision syndrome symptoms and improving eye comfort and focus. The rule is as follows: for every 20 minutes you view a computer display, look at an object 20 feet away (at a distance) for about 20 seconds. This gives your eyes a chance to “stretch” by relaxing your focus on something further away while also letting your convergence eye muscles relax.

4. Computer Specific Eyewear

A pair of computer vision specific eye glasses can help reduce focusing fatigue and blur.  These lenses would take into account your visual status, typical working environment, lighting conditions, and age.  Most patients I come across assume that if they have progressive lenses, or multifocals, that these types of lenses are able to work well on computer displays.  This is often not the case, especially as one approaches the age of 50.  A separate pair is often needed that is suited specifically for desk work.

5. Regular Visits to the Optometrist

Discussing your eye health concerns is paramount if you work on a computer all day. Your eye doctor can make sure you have the right prescription to avoid any unnecessary blur, over or under accommodation, reduce glare and discuss other solutions specific to you to prevent computer vision syndrome.

While it’s not possible to avoid computer work and time spent at digital screens, there are solutions to help remedy computer vision syndrome. Don’t let your eye comfort and health be compromised by your work, school or social demands!  Dr. Jeff Sciberras can identify problems and prescribe solutions specific to your needs. What are you waiting for?