More than half of all computer operators experience eyestrain, headaches, blurred vision and other symptoms directly and indirectly related to increased, sustained nearpoint visual stress. Visual stress also may underlie complaints of general body fatigue, reduced efficiency at work and higher error rates as the day progresses.
Optometrists have found that most of these symptoms are alleviated through a combination of correcting workstation conditions, posture, stress-relieving lenses prescribed specifically for computer operation, and in some cases, through improving visual skills with vision therapy.
Today, the majority of people, including children, are computer users. If what has been learned about vision and computers is ignored, millions will discover that visual stress can generate serious, often permanent vision and eye problems.
Humans have hunter-soldier eyes, essential to survival for spotting game or danger at a distance. But during the past half century, nearly all our work and much of our recreation has shifted to seeing within arm’s length.
The resulting near point visual stress, despite 20/20 distance visual acuity, often produces both temporary and sometimes permanent adaptive changes, including nearsightedness, suppressed vision in one eye, poor eye teaming and reduced performance both at work and at play.
Although computer manufacturers have vastly improved their products, some computer operators find their existing visual difficulties with near point visual activities are complicated by sometimes blurred characters, an increase in the number and complexity of necessary eye movements and focusing shifts, and by sometimes poor lighting conditions, glare and distracting reflections. Flicker also plays a role in visual stress.
Changes in the way work is done will affect many first-time computer users. Jobs which formerly allowed physical movement and opportunities to look away from near work now require extended, tiring concentration on a computer screen image.
Many people who could handle the visual stress of intermittent near work simply cannot deal with prolonged near point tasks.
Direct Visual Signs and Symptoms
- Headache accompanying or following computer use
- Eyestrain | Irritated eyes | Blurred vision
- Slow refocusing from close at copy /screen to distant objects
- Frequently losing place when moving eyes between copy /screen
- Difficulty seeing clearly at distances after prolonged computer use
- Occasional or frequent doubling of vision
- Changes in color perception
- Present lens prescription fails to relieve symptoms
Indirect, Visually-related Signs and Symptoms:
- Neck or shoulder tension, pain
- Back pain
- Excessive physical fatigue when using computer
- Irritability increases when using computer
- Pain in arms, wrists or shoulders when working
- Increased nervousness
- Lowered visual efficiency
- More frequent visual efficiency errors
If you suffer from any combination of direct or indirect conditions, it is time to have a Developmental Optometrist evaluate your visual skills and performance.
The optometrist’s recommendation may be the key to making work less stressful, less painful, and more productive. And, you may avoid the onset of more permanent visual and eye conditions now observed by optometrists among their computer-using patients
Symptoms and discomfort are the warning signs that something must be done to reduce the possibility of serious, permanent vision or eye problems that can alter and diminish the quality of life.
Computer Workstation Suggestions:
- Keyboard, screen and copy should, ideally, be at equal distances from the eyes.
- Computer screens should be slightly below eye level (about 10-20 degrees). Copy should be at the same level as the screen.
- Locate keyboard so wrist and lower arm are parallel to the floor or angled slightly downward.
- Chairs should provide proper back support and be adjustable without tools by the operator.
- Adjust chair height so feet are flat on the floor with thighs parallel to the floor.
- Adjust the worktable so legs and knees clear its underside.
- Screen brightness and contrast should be adjusted by the operator for maximum viewing comfort.
- Each workstation should have an adjustable shaded copy lamp that can be aimed by the operator without causing screen reflections or direct glare into the eyes.
- Eliminate glare and screen reflections by moving or tilting the screen. Overhead lights may need baffles. Try not to face toward windows or bright light sources.
- Operators should face into an open space beyond the computer screen.
- Clean computer screen regularly; they attract and accumulate dust.
- Adjust screen focus and image alignment frequently to reduce visual stress.
- Vision and performance are enhanced by taking a short break (15 minutes) every two hours. Demanding computer workloads usually require a short change from work each hour. Stop every 15 minutes to look up and away from the computer to focus on a distant object.