Computer Vision Syndrome (CVS)
Today nearly everyone uses computers for work, recreation, or education. Even the use of a smartphone requires our eyes to read a computer screen. Computer eyestrain affects more than 70% of the approximately 143 million Americans who work on a computer on a daily basis, according to the American Optometric Association (AOA). This major public health issue has led the field of optometry to address the effect it is having on our vision and upper body muscular structure.
The letters on a computer screen can be less sharp than those on paper copy, and the light reflected into the eye from the screen puts additional strain on our ability to maintain focus. This is further complicated by the need to adjust focus as we switch between screen images, other objects around us such as notes, phones, and the keyboard as we accomplish the task at hand. This constant refocusing becomes more difficult as we age and our lenses lose flexibility. Poor posture is encouraged by our attempts to adjust the viewing distance.
The distance from which most people view their computer screen is considered to be in the intermediate range, and falls outside of glasses used to drive a car and those used for reading. Special lenses are available to reduce the stress your eyes experience within this range.
There appears to be a correlation between the development of myopia (nearsightedness) and sustained computer use. Doctors are also researching concerns about the effect of exposure to the blue light emitted from digital devices. This light is also known a “high-energy visible”, or HEV, penetrates more deeply into the eye than ultraviolet light and may cause damage to the retina.
CVS has been linked to decreased productivity and an increase in data entry errors. Studies have also shown that treatment for CVS results in an increase in data entry speed and a significant reduction in errors.
Children and CVS
Children seem to be especially vulnerable to CVS. Researchers are investigating the harmful, long-term effects this may be having on their developing visual system, given the long, uninterrupted amounts of time they tend to spend in front of digital devices both at school and at play. Computer workstations are typically designed for adults, and don’t provide the needed posture support for children. If you suspect that your child may be suffering from CVS, be sure to mention this to your eye doctor, as they may wish to set aside additional time to perform tests specifically designed to detect computer vision problems
Computer Vision Syndrome Symptoms
Common complaints for this syndrome include:
- Watery or dry, irritated eyes
- Blurry or double vision
- Eye twitching
- Neck pain
- Stiff shoulders
- Worsening farsightedness, astigmatism, or presbyopia
These symptoms appear to be due to uncorrected vision, dry eyes, and poor posture.
Prevention and Treatment for Computer Vision Syndrome
Some common suggestions for the treatment of Computer Vision Syndrome include:
- Schedule a yearly eye exam to monitor CVS
- Consider the use of special glasses for CVS, or have an anti-reflective (AR) coating applied to your lenses
- Increase word font sizes
- Increase screen contrast to help text appear sharper
- Adjust screen brightness to match that of your environment
- Lower the color temperature of your display to reduce the amount of blue light emitted
- Install an anti-glare screen
- Adjust monitor placement to slightly below eye-level, 20” to 28” away from your face
- Replace an older CRT monitor with a newer flat panel LED monitor to eliminate eye strain caused by electronic “flicker”
- Choose a flat-panel display with a dot pitch of .28 mm or smaller, an anti-glare surface, and a diagonal width of at least 19”
- Use of artificial tears
- Take frequent short breaks (at least 5 min), stand up, walk away and stretch
- Reduce ambient light in the room, dim lights and pull window shades
- Use a good quality office chair with back support, arms should be parallel to the desk with feet resting on the floor
- Try to blink frequently to keep your eyes moist
- Place the print material on a copy stand adjacent to your screen or monitor for easy viewing
Suggestions for preventing children from developing CVS include:
- Obtain a comprehensive eye exam prior to starting school
- Ensure that the child’s computer work station supports their body size
- Place monitor 18” to 28” from and slightly below the child’s eyes
- The child’s arms should rest at the same level with the desk surface
- The child’s feet should rest comfortably on the floor
- Watch for frequent eye rubbing which may indicate eye fatigue
- Watch for posture related conditions, such as stiff neck or shoulders
Computer Vision Syndrome Glasses
Specialized computer glasses can make a life-changing difference. Glasses for distance and bifocals or reading glasses do not address the viewing distance required at a computer workstation. Even trifocals and progressive lenses have only a small portion of the lens dedicated to this intermediate viewing area.
Unlike regular eyeglasses, computer glasses are prescribed specifically for the distance from your eyes to your computer screen. The reduction in the demand for your eyes to refocus during computer use will lessen eye fatigue and reduce the risk for other computer-related vision problems. Almost any style of frame can be used for computer glasses.
If you have medical coverage, but not vision insurance, the exam portion of the cost may be covered by your medical carrier. If you have vision insurance, you may be entitled to an annual exam, which could be used to cover the computer exam and a portion of the cost of the computer eyewear.
Researchers at the University of Alabama School of Optometry recently concluded that due to productivity gains from workers wearing computer glasses, companies that pay for computer eyewear for their employees could experience a benefit/cost ratio of $18 for every $1 spent.
There are a number of special purpose lenses available that work well for computer glasses. Your eye doctor can help you determine which of them work best for you.
- Single vision lenses targeting your desired viewing distance
- Specially designed progressive lenses with a larger than usual intermediate zone
- Lined bifocal and trifocal lenses with larger intermediate and near zones
- Anti-reflective coating can be added to the lenses to reduce glare
- Lenses can be tinted to reduce ambient light that cannot be otherwise controlled
An exciting development is the availability of lenses specifically designed to block the short-wavelength, blue light that is emitted from digital devices. This segment of blue light, also known as “high-energy visible”, or HEV, penetrates more deeply into the eye than ultraviolet light and may cause damage to the retina. It has been shown to increase eye strain and may be linked serious long-term vision problems such as age-related macular degeneration (AMD) and cataracts.