Save Your Vision Month: Healthy Vision at the Computer

People who sit in front of a computer for long periods of time often encounter a variety of uncomfortable symptoms. Headaches, neck strain, backaches and wrist pain are common, but, sadly, the most prevalent symptoms of prolonged computer use-eye strain, blurred vision and dry eye-are often overlooked. In fact, eye and vision problems are the most frequently reported health care problems among computer users.

Computer Vision Syndrome

These symptoms contribute to computer vision syndrome, which the American Optometric Association defines as “the complex of eye and vision problems related to near work that are experienced during or related to computer use.”

Sitting at a computer generally causes a person to look straight ahead for long stretches, work in a dry office or home environment, and to blink less often. These factors can lead to vision problems. Additionally, computer use requires specific vision skills, which add further demands to the visual system and contribute to eye and vision discomfort. These skills include:

• Ocular motility — the ability of the eyes to move in various positions.
• Accommodation — the ability of the eyes to focus clearly at various distances.
• Vergence — The ability to move the eyes in (convergence) or out (divergence).

Effects Of Working Environment:

Computer work places various demands on the visual system. Each of these factors can play a part in computer vision syndrome.

• Screen resolution — Better resolution offers greater clarity and usually leads to improved comfort. Adjust the resolution to the highest resolution your monitor will support. If the increased screen resolution makes items too small, try increasing the font size (DPI) to compensate.
• Screen contrast — Adjust the contrast between the characters on the monitor and the background so the letters are easily read. Adjust the brightness of the monitor to an intensity that is comfortable to your eyes–not too bright and not too dim. Adjust both brightness and contrast for the best clarity.
• Screen glare and reflections — Minimize reflected glare on your monitor by using window treatments, dimmer switches on lights and glare reduction filters. Look for glare reduction filters that have received the American Optometric Association Seal of Acceptance. Proper adjustment should eliminate any reflected images from the monitor screen. To reduce glare, eliminate bright light sources from your peripheral vision and position your monitor perpendicular to windows or other bright light sources.
• Image refresh rates and flicker — A higher refresh rate for your monitor is best. The image on the screen should not flicker at all. (This is not a concern with LCDs.)
• Working distances and angles — It is important to work at a distance that is comfortable for you and where the image on the screen is clear. Having to move your head to an awkward angle to see the screen clearly suggests that your prescription may need adjustment.
• General eyeglass prescription may not be adequate — Computers are usually further and higher than a typical reading task. Glasses for most people wearing bifocals are not adjusted for this new distance or angle and therefore often are not adequate for using the computer.
• Repetitive and stressful tasks — Difficult tasks are challenging. Don’t forget to take occasional breaks and let the eyes look far away while resting.

Tips For Healthy, Comfortable Vision At A Computer:

While decreasing time spent at a computer may not be an option, there are ways to maximize healthy vision for comfortable use of the computer.

• Have a regular comprehensive eye exam to ensure your eyes are healthy and that you have the correct eyeglass or contact lens prescription (if necessary). Be certain to tell your optometrist about the computer work you do.
• Wear glasses that are specifically designed to function comfortably at the computer. The lenses you wear for day-to-day activities may not be the best for working at the computer.
  • Rest the eyes
  • Blink forcefully
  • Use a humidifier
  • Instill artificial tears

After you have had a comprehensive eye examination, there are a number of things that you can do to arrange and use the elements of your workstation to eliminate or minimize discomfort.

Workstation Setup for Comfortable Computer Use:

• Feet should be flat on the floor (or on a slightly angled foot rest) with knees bent close to or greater than 90 degrees.
• Chair seat should support the legs without excessive pressure on the back of the thighs.
• The back should be snug against the seat to fit your spinal contour. Thigh-to-trunk angle should be 90 degrees or greater.
• Wrists and hands should extend nearly straight from the elbow to the home row of the keyboard.
• A commonly preferred work surface height for keyboard use is about 26″ as opposed to the conventional 29″ of most tables or desks.
• Place the monitor 20″-26″ from your eyes, depending on the size of the monitor and individual vision conditions.
• The monitor and keyboard should be straight ahead.
• The top of the monitor should be slightly below horizontal eye level. Tilt the top of the monitor away from you at a 10 degree to 20 degree angle. The center of the monitor should be 10 degrees to 20 degrees below your eyes. This is 4?-9? below your eyes at a distance of 24″
• Keep the monitor free of fingerprints and dust. Both can reduce clarity.
• Place document holders close to the screen within the same viewing distance. Keep the keyboard and monitor in line.
• Adjust the keyboard tilt angle so that wrists are straight.

Healthy Computer Use:

Although the visual system faces considerable challenges when using a computer, most issues can be solved. Remember that problems with the use of the computer cause needless discomfort and may rob productivity. Heeding the suggestions made here along with those made by your doctor of optometry, will enable you to use your computer comfortably and productively. ~ American Optometric Association ~

For questions, or to schedule an appointment, contact:
Premier Eyecare, Julie Moore, O.D.
405.513.8150
http://www.okpremiereyecare.com

Impact of Computer Use on Children’s Vision

When first introduced, computers were almost exclusively used by adults. Today, children increasingly use these devices both for education and recreation. Millions of children use computers on a daily basis at school and at home.

Children can experience many of the same symptoms related to computer use as adults. Extensive viewing of the computer screen can lead to eye discomfort, fatigue, blurred vision and headaches. However, some unique aspects of how children use computers may make them more susceptible than adults to the development of these problems.

The potential impact of computer use on children’s vision involves the following factors:

• Children often have a limited degree of self-awareness. Many children keep performing an enjoyable task with great concentration until near exhaustion (e.g., playing video games for hours with little, if any, breaks). Prolonged activity without a significant break can cause eye focusing (accommodative) problems and eye irritation.

Accommodative problems may occur as a result of the eyes’ focusing system “locking in” to a particular target and viewing distance. In some cases, this may cause the eyes to be unable to smoothly and easily focus on a particular object, even long after the original work is completed.

Eye irritation may occur because of poor tearflow over the eye due to reduced blinking. Blinking is often inhibited by concentration and staring at a computer or video screen. Compounding this, computers usually are located higher in the field of view than traditional paperwork. This results in the upper eyelids being retracted to a greater extent. Therefore, the eye tends to experience more than the normal amount of tear evaporation resulting in dryness and irritation.

• Children are very adaptable. Although there are many positive aspects to their adaptability, children frequently ignore problems that would be addressed by adults. A child who is viewing a computer screen with a large amount of glare often will not think about changing the computer arrangement or the surroundings to achieve more comfortable viewing. This can result in excessive eye strain. Also, children often accept blurred vision caused by nearsightedness (myopia), farsightedness (hyperopia), or astigmatism because they think everyone sees the way they do. Uncorrected farsightedness can cause eye strain, even when clear vision can be maintained.
• Children are not the same size as adults. Since children are smaller, computers don’t fit them well. Most computer workstations are arranged for adult use. Therefore, a child using a computer on a typical office desk often must look up further than an adult. Since the most efficient viewing angle is slightly downward about 15 degrees, problems using the eyes together can occur. In addition, children may have difficulty reaching the keyboard or placing their feet on the floor, causing arm, neck or back discomfort.
• Children often use computers in a home or classroom with less than optimum lighting. The lighting level for the proper use of a computer is about half as bright as that normally found in a classroom. Increased light levels can contribute to excessive glare and problems associated with adjustments of the eye to different levels of light.

Steps to Visually-Friendly Computer Use

Here are some things to consider for children using a computer:

• Have the child’s vision checked. This will make sure that the child can see clearly and comfortably and can detect any hidden conditions that may contribute to eye strain. When necessary, glasses, contact lenses or vision therapy can provide clear, comfortable vision, not just for using the computer, but for all other aspects of daily activities.
• Strictly enforce the amount of time that a child can continuously use the computer. A ten-minute break every hour will minimize the development of eye focusing problems and eye irritation caused by improper blinking.
• Carefully check the height and arrangement of the computer. The child’s size should determine how the monitor and keyboard are positioned. In many situations, the computer monitor will be too high in the child’s field of view, the chair too low and the desk too high. A good solution to many of these problems is an adjustable chair that can be raised for the child’s comfort, since it is usually difficult to lower the computer monitor. A foot stool may be necessary to support the child’s feet.
• Carefully check the lighting for glare on the computer screen. Windows or other light sources should not be directly visible when sitting in front of the monitor. When this occurs, the desk or computer may be turned to prevent glare on the screen. Sometimes glare is less obvious. In this case, holding a small mirror flat against the screen can be a useful way to look for light sources that are reflecting off of the screen from above or behind. If a light source can be seen in the mirror, the offending light should be moved or blocked from hitting the screen with a cardboard hood (a baffle) attached to the top of the monitor. In addition, the American Optometric Association has evaluated and accepted a number of glare screens that can be added to a computer to reduce glare. Look for the AOA Seal of Acceptance when purchasing a glare reduction filter.
• Reduce the amount of lighting in the room to match the computer screen. Often this is very simple in the home. In some cases, a smaller light can be substituted for the bright overhead light or a dimmer switch can be installed to give flexible control of room lighting. In other cases, a three-way bulb can be turned onto its lowest setting.

Children have different needs to comfortably use a computer. A small amount of effort can help reinforce appropriate viewing habits and assure comfortable and enjoyable computer use.
~ American Optometric Association~

For questions, or a comprehensive eye exam, contact:
Premier Eyecare of Edmond, Dr. Julie Moore, #405.513.8150