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Protecting eyes from computer screen
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Eye problems
Computer and Health
By Dr Trisha Macnair
Most people give hardly a thought to the amazing work our eyes do to enable us to see, until things start to go wrong. It's often at work (or school) that people begin to realise they have a problem. That doesn't mean that work is harmful to your eyes (although it can be) but that work or school is where we most need to see well.
We may be stressed, tired, trying to read tiny print or study tiny diagrams, and using our brains to think out problems fast, relying on all our senses. And so often these days, work also means sitting staring at a computer screen or VDU which puts extra demands on our eyes.
Regular Eye Checks
So looking after your eyes at work is vital. But many people don't even have regular sight tests. It is estimated that as many as one in three working people have visual defects (like short or long sightedness) which have never even been diagnosed or have not been properly corrected. These problems may come to light when you do visually demanding work.
Make sure you have your eyes tested at least once a year or more often if you have symptoms. You may be able to demand that your employer provides regular eye tests especially if you work at a VDU - check Health & Safety regulations at: lhc.org.uk (vd02)
Symptoms suggesting eye problems are:
- Problems seeing or reading
- Blurred vision
- Headaches
- Dizziness
- Pain in the eyes
- Watery eyes
- Dry eyes
Eye Strain
Even if your eyes are healthy the job that you do can put extra strain on your eyes or cause other eye-health problems.
Eye strain means a sensation of tired eyes, which may be accompanied by increasing difficulty focussing or seeing, dryness, headache and general discomfort. Working at a computer screen or VDU greatly increases the risk of eye stain and may lead to Computer Vision Syndrome.
Tips to reduce eye strain
Make sure that the environment that you work in is eye-friendly:
- Arrange your desk so that you are a comfortable distance from the screen with a good posture and hand control at the keyboard. Your eyes should be about level with the top of the screen.
- Work from documents at an equal distance to your eyes as the screen so that you don't have to keep readjusting your focus. Use a vertical document holder attached to the side of your screen if it helps.
- Adjust the monitor controls until the brightness of the screen feels comfortable.
- Select a style and size of font (typeface) for your work which is most comfortable for your eyes to read - small fonts can actually causes rises in blood pressure and stress levels.
- Make sure that the contrast between light from the monitor and the room behind it is not too great, so that your eyes don't continually have to adjust between the two. Don't, for example, place your screen in front of a window or a very dark wall.
- Light the screen from above or behind you with a table lamp. Its generally recommended that the background lighting level is about 300-500 lux.
- Cover the monitor with an anti-glare device.
- Control levels of humidity in the air (dry air attracts dust and irritates the eyes) by placing vases of flowers or damp plants, or misting the air (but not too near the computer!).
- Take frequent short breaks (5-10 min per hour) allowing your eyes to refocus on something distant.
- While working swap frequently to tasks which don't involve the keyboard.
Risks of Long Term Harm
Some studies suggest that working at a VDU may increase health risks. For example, there may be:
- an increased risk of seizure in those with photosensitive epilepsy
- an increased risk of developing cataracts
- worsening of short-sightedness and less specific deterioration of eyesight
However, the majority of the research doesn't show any permanent health effects so it is likely that if there are health risks from a VDU, the risks are very small.
In some jobs there are very clear risks to the eyes from injury by particles or chemicals in the environment. If you work, for example, at machinery or where chemicals are released into the environment (for example, in mining, petroleum & oil refineries, chemical manufacturing & handling or laboratories) check with your health and safety officer about protecting your eyes. Check what you know by taking a workplace eye safety quiz ( preventblindness.org (worksafequiz) ) and follow Prevent Blindness America's 10 top tips to prevent injury ( preventblindness.org (prvnt-injuries) ).
- Always wear safety goggles when these are recommended, or face shields. Goggles form a seal around the eyes and stop objects, shards or particles getting into the eye. If ventilation holes are partially covered, goggles will also stop chemicals from splashing into the eye. Prescription glasses are not a substitute for safety glasses unless they meet the appropriate safety standards, usually shown on the frames with a safety eye wear logo. Contact lenses offer no protection.
- Always work with machine guards in place and following rules about working with chemicals.
- Know where the eye-bath station is in your workplace and what should be done is someone has an eye injury or contamination. In some places there are specially designed eye-wash sinks. Alternatively there should be portable squeezy bottles containing eyewashes. Its important to wash the eyes for a prolonged period, at least 15 minutes when there has been contact with caustic chemicals.
First Aid for eyes
First assess the situation quickly and get someone to close down all risks such as machinery, or move others from a contaminated area.
- Cuts to the eye.
- Don't wash the eye or try to remove anything stuck in the eye.
- Shield the eye with a plastic cup.
- Get urgent medical advice.
- Dirt or tiny particles in the eye.
- Use an eye bath to wash the eye copiously and flush out the particles.
- Don't rub the eye.
- Get medical advice if pain or particles persist.
- Chemical contamination ( intelihealth.com (9700) ).
- Flush the eye with an eye bath solution (or water if eye solution is not to hand) for at least 15 minutes and at least until you have had medical advice about the particular chemical.
- Get urgent medical advice.
- Trauma to the eye.
- Gently apply a cold pack to the area around the eye but don't put pressure on the eye itself.
- Get urgent medical advice, especially if there is pain, visual problems or blood or pus in the eye.
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I would like to have some points which will help me write my own notes on the topic: the social,ethical,legal and economic implications of computer use.
Here are some points to get you started:
Research, identify and discuss changing trends in computer
use as a result of developments in computer technology. Remember,
computers don't just include PCs, but anything with built-in computing
power such as mobile phones, CD/DVD players, digital cameras etc.
Explain why computers are best suited for tasks requiring
speed, accuracy and repetition.
Explain changes to society (consumers) brought about by the
introduction and use of computer systems.
Describe the impact of computers on jobs.
Health and safety
There are various health problems associated with the regular use of computers, and because of this employers must be aware of the regulations surrounding computer health and safety.
Employer regulations, General working environment, Possible dangers and solutions, Glossary.
Employer regulations. The law states that an employer must:
Provide tiltable screens, Provide anti-glare screen filters, Provide adjustable chairs, Provide foot supports, Make sure lighting is suitable, Make sure workstations are not cramped, Plan work at a computer so that there are frequent breaks, Pay for appropriate eye and eyesight tests by an optician.
Note:These regulations apply only to offices - not to students or pupils in schools or colleges.
In order to provide the satisfactory equipment for their employees, employers use ergonomics to assist the equipment design process. It is the science concerned with designing safe and comfortable machines for humans. This includes furniture design and the design of parts of the computer like keyboards.
Health at work - physical health
You don't have to work on a building site for your job to affect your health; even the more sedentary occupations can be a risk.
Back pain
Back pain is a fairly universal experience. Some see it as an inevitable legacy of our evolution, the result of turning a body designed to hang from a horizontal spine into a vertical spire, where a carefully balanced mechanism of muscles and joints must support organs and tissues pulling the column of vertebral bones downwards.
Back problems often start at work. Take an office worker who typically spends up to 40 hours a week hunched solid over their desk, nurses who need to frequently lift patients, a taxi driver bent into the driving seat for over 25,000 miles a year, a farmer constantly lifting sacks, seeds and machinery, or a checkout assistant sat on a poorly designed chair at her till all day (57% experience lower back pain each year). Our backs may be put under prolonged strain by our jobs and its hardly surprising that something within the delicate balance of bones and muscles so often fails.
Carpal tunnel syndrome
I'm seeing more and more people in my surgery suffering from carpal tunnel syndrome, and one of the things it appears to be related to, is using computer keyboards.
In the wrist, there is a tunnel formed by the strong tissue through which the tendons of the hand and the median nerve pass. It's a tight squeeze, so anything that reduces the space in the tunnel, such as fluid or inflammation of the tendon coatings, exerts pressure on this nerve. It's believed that repetitive overuse of the hand tendons, as with any tendon or muscle, causes them to become inflamed. Hence why keyboard use or other repetitive activities can be responsible.
When the nerve is compressed, people suffer discomfort, numbness, pins and needles, and sometimes, pain in the thumb, index, middle, and side of the ring finger, next to the middle finger. This is where the median nerve endings are distributed. Tingling often wakes sufferers up at night; when vigorously shaking the hands and arms is what brings relief. Men will also describe dropping things, or being clumsy with simple, but fiddly tasks, such as fitting a plug, for example.
