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Protecting eyes from computer screen
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Computer eye strain
Computer and Health
Very few jobs today do not require long periods of time in front of a computer. The great irony of course is that the human body is not designed to accommodate all the hours spent in front of a computer, and so we often end up with backaches, headaches, sore eyes and wrists, and a few extra kilograms. It is therefore important to manage your health through workstation planning and good work habits.
Your eyes and the computer
Staring at a screen for long hours places immense stress on your eyes because they were not designed to work at such a close range for long periods of time. Furthermore, the constant shift in focus (between the screen, documents and the keyboard) only makes matters worse and eventually you end up with a condition called eye strain.
Eye strain is an umbrella term for a wide range of symptoms including:
- Headaches
- Tired, sore eyes
- Eye irritation
- Blurred vision
When these problems are computer related, the condition is called computer terminal eye strain. Other symptoms include:
- Slow refocusing when looking from the screen to distant objects
- An inability to keep your place when moving your eyes between the screen and a document
- Having difficulty to focus on distant objects after using a computer for a period of long time
- Changes in colour perception
- An overall lowered visual efficiency, making more errors
Manage your workstation
Since it is impossible not to work on a computer, you have to manage your work environment to minimise stress on your eyes. The South African Optometric Association advises the following:
- Place your computer where you can look well beyond the screen every few minutes (i.e. not in front of a wall)
- Computer screens should be slightly below eye level (about 20 degrees). Documents being read should be at the same level as the screen
- Your screen should not be closer than 500 mm from your eyes
- Use indirect lightening at your workstation to minimise a glare from your screen. If it is possible, lighting should be beamed upwards to diffuse against the ceiling. If not, fit fluorescent ceiling lights with diffusers. Anti-glare screens are also available
- Use shaded desk lamps if necessary, and move your lamp if it reflects on the screen
- Don't place your computer too close to a window to avoid glare. Match as closely as possible the brightness of your surroundings with that of the computer screen. However, the contrast between the characters on the screen and the screen background should be high
- Adjust the computer contrast and brightness to achieve the most comfortable viewing level. These adjustments must be made at different times during the day if the work environment is influenced by altering levels of daylight
- Maintain your computer to avoid a reduction in brightness, contrast, flickering and legibility
- Clean the screen regularly as it attracts dust that reflects
Good work habits are also important. Look up and away from your computer screen every few minutes and take frequent short breaks (every 10v15 minutes). Most importantly, have a comprehensive optometric examination annually and make sure that your optometrist knows about your current computer use.
H. Perold
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Health & safety
Because there are so many children of varying ages and sizes in a before
and after school care program, it is essential to pay attention to health
and safety issues. Children need to be taught simple safety principles from
the time they begin using computers. Don't overlook the obvious when children
use computers. For children as well as adults, bad posture can cause sore wrists, eye fatigue, headaches, neck strain and even back pain. Since kids may be using computers both at home and at school, there is the potential for problems to develop over time.
To prevent eye problems, avoid flickering lights or glare on the screen, and look away from the monitor frequently. (This is true for video games also.) Get up and walk around (moving around rests both the eyes and the body), focus on a distant object, remember not to stare at the screen, and blink often.
Furniture that is used should be safe and adjustable so it fits each child. If you can't find sturdy, adjustable furniture, have some available that fits the different sizes of the children using it. Because many sizes and shapes of children will probably be using a computer area that has been set up for one "size" of students, careful monitoring of the physical set up should occur when each new student sits down. Make the appropriate adjustments for each child according to the guidelines listed below.
FAQs on myopia
Q. What is myopia?
A. Myopia is commonly known as "short-sightedness". A person with myopia is able to see close objects clearly but objects that are further away will appear blurred.
When the normal eye looks at an object, light rays from the object enter our eye. These light rays are bent at the cornea and the eye lens before forming an image on the inner layer of the eye called the retina. This image is then transmitted by nerve signals to the brain. The brain interprets these signals so that we see the object.
If the light rays are focused directly on the retina, we see a sharp image. Myopia occurs when the light rays from distant objects are focused in front of the retina instead of on it, resulting in blurred images on the retina. This is usually because the eyeball is too long or sometimes the cornea and lens do not bend the light rays properly.
Q. What are the complications of myopia?
A. Undetected myopia before the age of 6 years old can lead to amblyopia (lazy eye) and eventually blindness in the affected eye.
Severe myopia can lead to potentially blinding conditions such as _ retinal detachment (a condition when the retina separates from the eyeball)
Your health - headaches and eye strain
What are headaches and eyestrain?
Headaches can be caused by many different factors and are one of the most common reasons people visit their GP. Most headaches are not serious and usually disappear on their own. They can be relieved by mild painkillers, or a positive change in lifestyle.
Eyestrain is also a common complaint among people doing 'close' work e.g. those who work using computer monitors. Eyestrain can be a trigger for headaches, but can usually be avoided by following simple guidelines.
What are the signs of headache or eyestrain?
A headache can range from a mild, throbbing feeling to a sharp, stabbing pain. Headaches can affect your whole head or just a part of it. The pain may move around, affect your vision or even cause nausea and vomiting. The two most common types of headache are tension headaches and migraine.
Tension headaches do not usually last for a long time. Common symptoms of a tension headache include
Eye discomfort in the office
What is the significance of "good" lighting? Office work is visually demanding and has always required good lighting for maximum comfort and productivity. "Good" lighting means providing enough illumination so that people can see printed, handwritten or displayed documents clearly but are not blinded by excessively high light levels (a cause of glare). The introduction of computers in the 1970's increased the visual demands of office work and made lighting design even more challenging. While typewriters were being exchanged for computers, the need for redesigning or rearranging office lighting was commonly overlooked.
What are signs of poor lighting? The most common complaints resulting from poor lighting are: eyestrain, eye irritation, blurred vision, dry burning eyes, and headaches. Poor lighting affects not only the ocular system but can also contribute to stiff necks and aches in shoulder area. These problems can occur when people adopt poor or awkward postures when trying to read something under poor lighting conditions.
Vision / eye strain
Visual problems, such as eyestrain and irritation, are among
the most frequently reported complaints by computer operators. These
visual symptoms can result from improper lighting, glare from the
screen, poor positioning of the screen itself, or copy material that is
difficult to read. These problems usually can be corrected by adjusting
the physical and environmental setting where the computer users work.
For example, work stations and lighting can and should be arranged to
avoid direct and reflected glare anywhere in the field of sight, from
the display screen, or surrounding surfaces.
You also can reduce eyestrain by taking vision breaks, which
may include exercises to relax eye muscles after each hour or so of
operating a computer. Changing focus is another way to give eye muscles
a chance to relax. You only need to glance across the room, or out the
window, from time to time and look at an object at least 20 feet away.
Other eye exercises may include rolling or blinking the eyes, or
closing them tightly for a few seconds.
