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Computer vision syndrome (CVS) is a term that describes eye-related problems and the other symptoms caused by prolonged computer use.
As our dependence on computers continues to grow, an increasing number of people are seeking medical attention for eye strain and irritation, along with back, neck, shoulder, and wrist soreness.
These problems are more noticeable with computer tasks than other near work because letters on the screen are formed by tiny dots called pixels, rather than a solid image. This causes the eye to work a bit harder to keep the images in focus.
There is no scientific evidence that computer screens are harmful to the eyes. A common myth is that eye strain caused by reading and close work is damaging to the eyes. This is not true; however, those who work at computers often experience many frustrating symptoms.
Signs and Symptoms
- Blurred near vision
- Difficulty focusing from close to far and back again
- Sore, irritated eyes Dry eyes
- Red eyes
- Eye fatigue
- Headaches that disappear after a period of rest
- Irritation and discomfort while wearing contact lenses
- Soreness and pain in the neck, shoulder, and back.
Detection and Diagnosis
Your eye care practitioner will perform a complete eye examination that includes: near and distance visual acuity, refraction, tonometry, and an examination of the eye structures with a slit lamp microscope and ophthalmoscopy.
It is important to provide the eye care practitioner with detail about your work environment, work habits, and detail about the symptoms and their patterns. Bring your prescription glasses with you so the eye care practitioner can determine if they are appropriate for computer work.
Treatment
The three main areas that should be addressed when treating CVS patients are: eye-related problems, work environment, and posture.
Eye-related problems
- Make sure the glasses are the correct prescription and designed for working at a computer. Patients who wear bifocals may find themselves keeping their head in an uncomfortable position in order to see the screen. Your optometrist will determine the glasses best suited for the task, and if necessary, prescribe glasses with an adjusted bifocal height and width.
- Blink frequently and instill artificial tears as needed. One of the biggest complaints of patients with CVS is dry, irritated, red eyes. This is common because we tend to blink less when reading.
- Stop periodically and look away from the computer screen. Looking up relaxes the eye's focusing mechanism and reduces the problem of eye strain.
- The time taken for the rods of the retina to become active.
Work environment
- Sit approximately 24" from the monitor. Sitting at the appropriate working distance from the computer screen maximizes the clarity of the text and images.
- Adjust the monitor so the centre is slightly below eye level. This keeps the neck in the most natural position and reduces soreness and fatigue.
- Minimize glare on the screen. Arrange the lighting and desk to eliminate glare on the monitor. An anti-reflective screen placed over the monitor is sometimes helpful.
Posture and work habits
- Maintain good posture. Sitting up straight with your feet on the floor can reduce back stress. Use a cushion for the lower back if necessary.
- Keep your wrists straight when typing. Avoid resting your wrists on the keyboard.
- Place the mouse and keyboard at
the same level, keeping them close to the body. The keyboard level
should at a slightly lower level than the desk.
Computer Vision Syndrome and Children
The average American child now spends one to three hours per day on the computer doing homework, talking online with friends, and playing games.* Parents encourage children as young as two or three years old to use the computer. In fact:
- 90% of school-age children have computer access at home or in school.
- 54 million children in the United States alone use a computer at home or in school.
Many pediatric computer vision eye doctors believe that heavy computer use among children puts them at risk for early myopia. They point to several recent studies as evidence that computers can have a negative impact on a child's vision:
- 25% to 30% of computer-using children need corrective eyewear to work comfortably and safely at the computer at home or in school, says a study at the University of California at Berkeley School of Optometry.
- The percentage of first-graders with myopia has increased from 12.1% to 20.4% since 1995, according to a study by the Department of Health in Taiwan.
A similar study in Singapore found that in three years the percentage of seven- to nine year olds with myopia had doubled, to 34%. Sitting for hours in front of a computer screen stresses a child's eyes because the computer forces the child's vision system to focus and strain a lot more than any other task. Twenty years ago, most children played outside, and their distant vision was more important.
Today, most children work at a computer either at home or school each day. Sitting in front of a computer and staring at a computer screen is causing vision problems that were not known years ago. Today it is a "near-point world," and parents need to be aware of the vision problems associated with computer work.
Computer use demands fine motor skills from young eyes that are not well developed. Only when the visual system matures is a child better able to handle the stress of a computer on that system.
According to the American Optometric Association, the impact of computer use on children's vision involves these factors:
- Children have a limited degree of self-awareness. They may perform a task on the computer for hours with few breaks. This prolonged activity can cause eye focusing and eye strain problems.
- Children are very adaptable. They assume that what they see and how they see is normal — even if their vision is problematic. That's why it is important for parents to monitor the time a child spends working at a computer.
- Children are smaller than adults. Since computer workstations are often arranged for adult use, this can change the viewing angle for children.
Computer users should view the screen slightly downward, at a 15-degree angle. Furthermore, as a result of difficulty reaching the keyboard or placing their feet on the floor, a child may experience neck, shoulder and/or back pain.
Tips for Preventing Computer Vision Syndrome in Children
Many pediatric eye doctors believe that environmental stress of the "indoor world" rather than heredity is creating the myopia (nearsightedness) epidemic. In fact, children using computers before their visual systems are fully developed are at the very heart of the public health problem called computer vision syndrome. To prevent your child from suffering from CVS, follow these tips:
- Before starting school, every child should have a comprehensive eye exam, including nearpoint (computer and reading) and distance testing.
- Workstations should be arranged to suit a child — not an adult.
- The recommended distance between the monitor and the eye for children is 18-28 inches. By viewing the computer screen closer than 18 inches, children risk straining their eyes.
- Parents and teachers should be aware of any behaviour that indicates potential problems, such as eye redness, frequent rubbing of the eyes, head turns and other unusual postures, or complaints of blurriness or eye fatigue. Avoidance of the computer may also be an indication of discomfort.
Computer Vision Syndrome FAQ
Will Glare Screens Prevent Computer Vision Syndrome?
Glare screen filters may help somewhat, but they will not solve your computer vision problems because they only affect glare from the computer screen — not the visual problems related to the constant refocusing of your eyes when working at a computer. Only when your eyes can focus clearly at the plane of proper distance on the computer screen can they experience relief from the fatiguing effects of CVS. An anti-reflective coating (ARC) is also highly recommended on all computer eyeglasses. An Anti Reflection Coating prevents glare and reflections on the front and the back of the lenses that would interfere with focusing on the screen.
Will Computer Spectacles Make the Screen Clearer?
Yes, because they will eliminate the constant refocusing effort that your eyes go through when viewing the screen. It has also been proven clinically that having the correct prescription in computer eyeglasses increases productivity and accuracy.
Do Computer Spectacles Look Like Safety Glasses?
No. Almost any style of frame can be used for computer eyewear. More important are the lenses that your eye doctor chooses for your computer eyeglasses. Ninety percent of the time, multifocal lenses will be your best choice, as they are designed specifically for working at a computer. They allow you to see clearly at your correct computer screen distance and can give you some distance vision beyond the computer. But whether the lenses are multifocal or single vision, you and your eye doctor must determine the best lenses for your work environment.
What About the Tints I've Heard of for Computer Lenses?
If you work in a brightly lit office, you may benefit from a light tint applied to your computer lenses. This can cut the amount of light that reaches your eyes and provide relief in some cases. But tints and filters don't address the underlying cause of computer eyestrain.
Does Every Computer User Need Computer Glasses?
More than 70% of computer users need computer eyeglasses. In fact, according to a study out of the University of California, Berkeley, 25%-30% of children would benefit from computer eyewear.
If I Don't Have Symptoms of CVS, Do I Still Need Computer Eyewear?
Maybe. According to a University of Alabama study (2004), computer users
who are not experiencing symptoms of computer vision syndrome may also
need computer eyewear. The study reports that it does not matter whether
subjects reported symptoms of CVS. The fact is that viewing a computer
screen is a different stimulus for the eyes than reading printed materials.
It is much more difficult for the eyes to focus on pixels than on printed
characters.
Individuals with no visual problems may still be losing productivity
and accuracy at the computer. This is the number one reason to get a
regular eye exam from a computer vision specialist.
Will My Reading Glasses Work at the Computer?
Not necessarily. As with anything else you do in
life, it is important to have the right tool for the job. You would not
use a hammer when you need a screwdriver. The same goes for your vision:
you would not use distance glasses for doing close work. So in most cases
your reading glasses are probably not going to do the job. The correct
computer eyeglasses will optimize your comfort and productivity at the
computer screen while also allowing you to read and see out at some determined
distance (10-13 feet). Reading glasses are usually prescribed to read
at a distance of 16"-18", but computer glasses are usually
designed to work at 18" to 28".
Is It True That if a Person Doesn't See the Computer Screen Clearly, He May Not Be as Productive?
Yes, but in cases where the correction is only slightly off, the computer user may think he is seeing the screen clearly. Yet a recent study at the University of Alabama found that over time even the smallest miscorrections can cause big problems down the road, including loss of productivity and accuracy in the workplace. The eyes viewing a computer for many hours a day is analogous to the eye muscles being forced to do push-ups for hours and hours. Over time, these push-ups will significantly affect productivity, accuracy, and comfort.
Isn't Ergonomics the Solution to Computer Eyestrain?
Ergonomics is important — changing one's computer workstation can certainly help to minimize other physical symptoms. But ergonomics cannot fix a visual problem. The proper prescription computer spectacles at the proper computer distance (18" to 28") is most important. This can be done only with the right computer lens prescription.
Is It True That Wearing Computer Spectacles Will Make My Eyes Worse?
This
is not true. In fact, prescription eyeglasses can prevent further damage
to the eyes. Depending on your prescription, an eyecare professional
will probably fit you in either single vision or multifocal lenses. The
single vision lens is designed to optimize your vision at one distance
only: near for reading or work at the computer; or far for distance (watching
a movie or driving). Many eyecare professionals are now fitting computer
users in a multifocal lens that has a wide intermediate zone, which
optimizes computer work. This lens also allows the wearer to read printed
material while working at the computer and see a limited distance (10
to 13 feet). It is true that your eyes will get worse if you continue
to stress the eye muscles and do not wear prescription eyeglasses.
