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Protecting eyes from computer screen
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Health & safety
Computer and Health
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.
- Don't sit too close to the monitor
- Take frequent rest breaks and "eye breaks"
- Stand up, stretch and wiggle often
- Blink frequently
- Avoid using the mouse for long periods of time
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.
Ergonomic Guidelines
Viewing Distance: The monitor should be at least 2 to 2 1/2 feet from the child's eyes. To encourage children to maintain the proper distance make the screen easy to see and read at that distance. A larger size font or print on the computer screen, such as 14 or 16, may be helpful. The print can also be adjusted for boldness, color, and line spacing to make it easy to read.
The top of the monitor should be at forehead height so that the child looks slightly down. The child should not have to lean back or forward to see the work on the screen.
Time at Computer: Children should not be encouraged to spend lots of sedentary time at a computer. They should be encouraged to use their physical energy. Little kids wiggle-so let them wiggle, stand up, sit on their knees, or change positions while working at the computer. If they continue to move around during their computer time, they will be healthier and have fewer injuries.
Seat Height and Posture: The child should sit high enough so that his or her arms bend at 90? angles when typing or using the mouse. If the height of the chair is not adjustable, use cushions, foam rubber, or even a phone book on the seat to raise the child up high enough. If the child wants to stand or sit in a more comfortable position, that is all right-sitting up straight may not be the most comfortable posture for the human body. The correct posture for working at a computer is one that provides comfort and circulation to the back, arms, legs, and neck.
Footrest: If the child sits in a chair and his or her feet do not touch the floor, use a footstool or footrest to prevent feet from dangling and cutting off the circulation in the legs. Use cushions, phone books, or boxes if a footrest is not available.
Mouse, Touch Pads and Rollerballs: Most computer mice are built to fit adult hands, not child-sized hands. Try to find a mouse that fits small hands, and place it within easy reach of the child.
Most children do not have highly developed motor skills for using a mouse. Touch pads and rollerballs are great options for kids because they are easier to manipulate than a mouse.
Keyboards: Child-sized or notebook keyboards are best for young children because the keys are small and close together. The keys should need only light pressure so that keyboarding does not tire their hands and so that children don't pick up the bad habit of pounding keys to get them to work.
For additional information and examples on Computer Ergonomics for Elementary School visit the Oregon Public Education Network Web site.
Internet Safety Concerns
Adult supervision and guidance are the best safety measures for young children. Place computers in common areas where they are easily visible, and monitor children's time on the computer. Any use of the Internet should be with adult guidance.
The American Academy of Pediatrics offers additional information on the Internet and your family.
Health & Safety issues
It is important to realise that working with computers, particularly for long periods of time, can be dangerous to your health. To create a safe working environment, the following factors should be considered.
Specific Risks:
Repetitive Strain Injury (RSI) - This is caused by repetitive finger movements over long periods of time and can cause serious pain in the finger joints.
Solutions - to reduce the risk of RSI you should:
- have your keyboard positioned correctly
- use a keyboard with a good ergonomic design
- develop a good typing technique
- try using wrist supports placed in front of the keyboard
- take regular breaks from using the keyboard
Special, ergonomically-designed keyboards where the keys are split and contoured for the hands, can be purchased.
Eye Strain - Eye strain is quite common among people using monitors over extended periods of time. It can result in irritated eyes and blurred vision.
Solutions - to reduce eye strain, users should look away from the monitor and focus on a distant object from time to time to relax their eye muscles. A screen glare deflector can help some users.
All new monitors must comply with EU standards which ensure that radiation emission is as low as possible and all new screens must be fitted with tilt and swivel stands.
Room lighting can have a major effect on eye strain.
- Windows should be fitted with non-reflective blinds, preferably beige in colour.
- Computers should be positioned so that sunlight from the window does not reflect on the screen.
- The optimum position is at right angles to the source of natural light.
- Worktops should have a matt surface in order to reduce glare.
Back problems - Sitting at the computer for long periods of time is never comfortable. Leaning back in the chair reduces the pressure on the spine but then the arms have to reach forward to the keyboard creating muscle tension which leads to aches and pains in the neck, shoulders, back and arms.
Solutions - while working at the keyboard, the correct seating position is sitting upright with the feet flat and the lower arms and thighs in a roughly horizontal position. Adjustable chairs that give the maximum support for the back are also best.
Sufficient room is needed for the monitor to be moved back and forward. Ideally, the top of the monitor should be at eye level.
Worktops should have a fixed height between 660-730mm is required (720mm is recommended). A worktop depth of 760-840 mm is required to give the user sufficient distance from the screen while working.
Even with a comfortable working environment, it is still good to stand up, stretch and move.
Power supply:
- Computers are generally connected to 240v mains electricity and must be treated with care. The computer should be properly earthed and the plugs should have the correct fuses
- Trailing electrical leads should be avoided to reduce the risk of tripping or them being damaged.
- Leads should preferably be in trunking or be safely tied out of the way
- There should be enough power sockets to avoid power sockets being overloaded
- Mains plugs and leads must be checked for safety once a year
- If the computer is moved or opened, the power cable must disconnected
Fire risks:
In case of a fire, the fire extinguishers should be powder-based or CO2 (carbon dioxide) devices. Water-based fire extinguishers should not be used on electrical appliances.
Food and Drink:
It is best to avoid eating and drinking near to computer equipment. Food crumbs can prevent a computer mouse or keyboard from working properly. Any spilt liquids are a possible fire risk near electrical equipment and can easily ruin items such as floppy disks.
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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.
