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.

Why do computers create a challenge for lighting designers?

The monitor itself is a source of light. As such, it does not require additional illumination from other sources. In fact, the screen itself can cause glare if the brightness and contrast controls are not properly adjusted.

An additional challenge occurs because most office work involves using the monitor and paper documents at the same time. Paper documents require a higher light level than the monitor. A desk lamp (any type of soft task light) can be used to illuminate documents while avoiding excessive light near the monitor. Glare can also result from an improper match or excessive contrast in light levels between the monitor screen and the paper.

The monitor also acts as a mirror. Reflections of objects, shiny walls, and any light source (specifically windows and overhead lighting) all cause glare. Eye discomfort can result but glare also forces the user into an awkward position as they try to avoid having the glare in their eyes. These positions lead to aches and pains in the upper body that, in turn, can also aggravate eye strain!

The quality of the images on the monitor is another important factor. Reading and interpreting blurred, fuzzy, tiny, or otherwise illegible characters for hours a day can strain the operators' eyes.

What else in the computerized office contributes to the eye discomfort?

Other examples of work-related risk factors that contribute to eye discomfort are:

• maintaining a fixed and close visual distance for a long time,
• glare from the unshaded or un-diffused lighting fixtures,
• poor lighting, involving unchanged (and unchangeable) levels of illumination,
• unsuitable workstations (dimensions and arrangement),
• low ambient humidity,
• uncorrected vision problems, and
• lack of colour variety in one's surroundings.

Are there any non-visual effects of poor lighting?

When people are exposed to glare or have uncorrected vision problems, they tend to lean forward or backward in an attempt to compensate. An awkward body position leads to eye strain and accelerates postural fatigue that, in turn, contributes to musculoskeletal injuries (MSI).

How can eye discomfort be reduced?

Overhead lighting

• Use filters to diffuse overhead lighting.
• Dim overhead lights.
• Keep in mind that recommended level of light in offices 300 - 500 lux is not a must. It applies in the situation where there is no task lamp in use.

Windows and walls

• Cover windows with adjustable blinds.
• Use matte finishes on walls, floors and furniture.

Monitor

• Adjust the brightness and contrast according to your preference.
• Use a light colour for the background.
• Place the monitor parallel (not directly below) with overhead lights.
• Angle the monitor away from lights and windows.
• Make sure that the task lamp illuminates the document and not the monitor.

Should anti-glare screens be used?

In general, anything between the operator and screen compromises the quality of the image. It is far better to control glare by proper lighting design and placement of the monitor than by use of an anti-glare screen. Many monitors currently available are already equipped with low reflective screens.

What can you do to reduce eye strain?

The ability to focus on objects at various distances decreases with age (presbyopia). Commonly, by their forties people cannot clearly see objects at close range with the naked eye. This is a gradual change, and has to be regarded as an important component in designing visual environments, particularly when the job involves computer work. Uncorrected vision may be an additional source of eye discomfort. It may have further consequences resulting in aches and pains because of awkward postures or positions adopted to "see better".

• Check your vision every one or two years, as recommended by your eye specialist.
• Provide your eye examiner with information about your job.
• Consider using task-specific computer glasses.

Depending on the amount of time you work at a keyboard, the kind of vision correction needed, and your personal preferences, your eye specialist may recommend bifocals, trifocals or even a separate pair of glasses for computer work.

Focusing your eyes on objects at the same distance and angle for prolonged periods of time can contribute to eye strain.

• Every few minutes look away from the screen for a few seconds.
• Look around.
• Focus your vision on distant objects.
• Blink several times.

Frequently "stretching" your eyes like this will prevent feelings of fatigue from accumulating.

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.

Inadequate vision can strain your posture as well as eyes -- have your eyes checked annually, you may need special glasses

This section provides links to information and resources regarding vision and eye strain issues while working at Video Display Terminals (VDTs).

Articles

Improving Visual Comfort at a Computer Workstation by Dr. Jeffrey R. Anshel, BS, OD

Visual discomfort occurs at a computer workstation when the visual demands of your task exceed your visual abilities. The problem can be resolved by treating your visual condition, if any, or by making your visual task less demanding.

Vision Health Management: Visual Ergonomics in the Workplace, Dr. Jeffrey R. Anshel, BS, OD

Vision is our most precious sense. Our eyes are in constant use every waking minute of every day. The way we use our eyes can determine how well we work throughout our lifetime. Over 80% of our learning is mediated through our eyes, indicating the important role our vision plays in our daily activities. Vision disturbance is a silent enemy that only appears after a long period of continued stress.

Kids and Computers: Eyes and Visual Systems, Dr. Jeffrey R. Anshel, BS, OD

Today, millions of children are using computers every day, at school and at home, for education and recreation. Visual demands in school require the integration of a number of different vision skills: visual acuity (sharpness of vision); visual fixation (eye aiming); accommodation (focusing); binocular fusion (forming a single image); convergence (turning of the eyes); field of vision (side vision); and form perception (recognizing shapes). These systems can be stressed and overworked if not used efficiently. Computer viewing is complicating how children use their eyes in school because these visual skills are not yet fully developed in children?making any near-point activities that much more difficult.

Vision, Reading and Computer Users

An Interview with Distinguished Optometrist, Dr. Gary J. Williams

http://webword.com/interviews/williams.html

Websites

The Relationship of Computer Vision Syndrome to Musculoskeletal Disorders

American Optometric Association

http://www.aoanet.org/ia-musculo.html

Eyestrain Basics

http://www.ur-net.com/office-ergo/12things1.htm

http://www.office-ergo.com/12things1.htm

IBM's Healthy Computing - Vision

http://www.pc.ibm.com/us/healthycomputing/ergoviso.html

Computers and Eyestrain by E. Lawrence Bickford, O.D.

http://www.west.net/~eyecare/computers_and_eyestrain.html

Causes, symptoms and treatments for computer-related eye strain.

Reducing Eyestrain from Video and Computer Monitors by Charles A. Poynton

http://www.inforamp.net/~poynton/notes/reducing_eyestrain/

Preventative Measures Ease Computer Eye Strain and Other Health Problems

http://www.aoanet.org/nr-preventive.html

Computers and Eye Strain

American Academy of Ophthalmology - eyeNET

http://www.eyenet.org/public/faqs/computers_faq.html

Computer Vision Syndrome

http://www.cvconsulting.com/articles.htm

Articles by Dr. Jeffrey Anshel

PC Magazine Online: Your Eyes Come First

http://www8.zdnet.com/pcmag/issues/1418/pcm00049.htm

Jim Seymour's article about eyestrain and the PRIO eye test.

Computerized Home Vision Therapy Systems

http://www.homevisiontherapy.com/

Treatment for eye strain, computer vision syndrome, and children's learning problems

Eye2Eye: The Computer Eyestrain Journal

http://www.eye2eye.com/

Eye2Eye's mission is to help control vision difficulties associated with prolonged exposure to computer screens. Collectively, these symptoms have been termed Computer Vision Syndrome (CVS) by the American Optometric Association.

Computer eye strain

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

What things should you do if using a computer for a long time for Health reasons?

Computer work can be quite strenuous for the body, especially for the eyes, the back, the wrist and the hand.

The first thing to do is to have a good position in a nice environment: comfortable straight chair, monitor and keyboard at the right height and distance, quite room, well lit.

There are several ways to minimise eye strain. Modern flat screens are better than standard monitors. Also, special screen filters that fit in front of a monitor are good for the eyes.

Also, you may have heard of RSI, repetitive strain injury, a condition that affects the wrist and the hand and is provoked or compounded by extensive use of the mouse. A few things can help minimising the risk of this are: trying to use more keyboard shortcuts, moving the hand away from the mouse when not needed etc.

The most important thing is to take regular short breaks away from the screen and to do some stretching or get some fresh air in order to relax the mind and the body. But don't use that information to walk out in the middle of your next ICT lesson.

Can you tell me two health and two safety risks that need to be considered when using computers, or just give examples because i don't understand the difference?

Health & Safety risks include anything that can affect your well-being, physical fitness or endanger your life. Here are some ideas of what type of risks these include with regard to computer equipment:

Health

• Using laser printers can affect your health if they are not properly positioned in a ventilated space. This is because fumes are given off when the printer is going through the process of producing a printed page.
• Using computer equipment can affect your health if it is not correctly and ergonomically set-up. By this we mean - correct desk, chair and keyboard heights; proper positioning of monitor and lighting around it; use of wrist rests for mouse and keyboards. The health effects of poorly set up working environments can include eye strain; repetitive strain injury on joints and muscles; back aches.

Safety

• Correct installation of devices and enclosure of wires, leads and other electrical points is essential to avoid accidents. Appointment of qualified electricians is necessary in an office environment to safely install trunking and power supply for computer equipment.
• Proper earthing of devices such as monitor anti-glare/static screens to avoid shock or blowing fuses.
• Regular maintenance and upkeep of computer equipment is needed to avoid safety issues. For example, faulty monitors or internal cooling fans that may lead to overheating of equipment.

It is the responsibility of an employer to ensure that the Health & Safety at Work Act is complied with and that these risks are assessed and properly addressed. It is the responsibility of the employee to correctly adhere to regulations and guidance and to report faults and risks in order to avoid endangering their own (and other colleagues') health and safety.

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:

1. 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.

2. Explain why computers are best suited for tasks requiring speed, accuracy and repetition.

3. Explain changes to society (consumers) brought about by the introduction and use of computer systems.

4. Describe the impact of computers on jobs.

5. Discuss steps which can be taken to protect confidentiality of data held on computer systems.

6. Understand the need for data protection legislation.

7. Discuss the social and ethical implications of access to information whose value is controversial.

8. Discuss health and safety implications (for example, repetitive strain injury (RSI) of increased computer use, including measures to ensure a healthy and safe working environment for employees.

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.

General working environment

Don't forget that rules for all electrical appliances apply in a computer room. This means:

• There should be no trailing wires
• Food and drink should not be placed near a machine
• Electrical sockets must not be overloaded
• There must be adequate space around the machine
• Heating and ventilation must be suitable
• Lighting must be suitable with no glare or reflections
• Benches must be strong enough to support the computers.

Possible dangers and solutions

Within Information Technology it is important that people have an awareness of the various health and safety issues. Steps should also be taken towards preventing common problems rather than trying to cure them at a later date.

Back problems

Many computer users suffer serious back problems. This is probably due to a poor posture or an awkward position while sitting at a computer.

Solutions

A fully adjustable chair should avoid poor posture

Footrests can reduce these problems

Screens should tilt and turn to a position that avoids awkward movements

Repetitive Strain Injury (RSI)

Repetitive Strain Injury (RSI) is damage to the fingers, wrists and other parts of the body due to repeated movements over a long period of time.

Solution

To prevent RSI, make sure your posture is correct, use wrist rests and have a five-minute break from typing every hour.

Eyestrain

Eyes can become strained after staring at a computer screen for a long time, particularly if working in bad light, in glare or with a flickering screen.

Solutions

Screen filters can remove a high percentage of the harmful rays emitted from a computer screen

Use screens that do not flicker

Take regular breaks - do not work for more than one hour without a break

Lighting must be suitable and blinds fitted to windows to reduce glare

Ozone irritation

Health experts have suggested that ozone emitted from laser printers can lead to breathing problems.

Solution

It is recommended that laser printers should be situated at least one metre away from where people are sitting and there should be good ventilation in the area.

Glossary

Ergonomics

Ergonomics 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.

Repetitive Strain Injury

RSI - damage to the fingers,wrists and other parts of the body due to repeated movements over a long period of time.

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.

Conditions such as rsi, carpal tunnel syndrome, headaches - and back and eye problems can all be avoided if you're aware of the causes and do your best to minimise them. If you use a computer, the practice of good workstation ergonomics can help.

In this section, we also look at the impact that shift work can have on your physical health - and we include a feature on sick building syndrome.

Back Pain

By Dr Trisha Macnair

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.

Why do we get back problems at work?

Back problems at work are the result of abnormal strains put on the spine, which lead to damage to the tissues. These strains may be sudden (e.g. lifting a heavy load awkwardly) or chronic (spending hours in a certain posture). The result is traumatised, bruised or inflamed muscles (which may go into spasm), damaged ligaments, misalignment of tiny vertebral joints or damage to the discs between the vertebrae. Sometimes a back problem directly follows an injury but often it appears quite unrelated to any specific event. It can be difficult to establish clearly what damage has been done to the back (back pain is too common to routinely use expensive MRI scans to investigate the problem) but there is no denying the misery of back pain.

Abnormal strains on the back at work are more likely if:

• You are generally unfit - this makes all injuries more likely.
• You are overweight: this puts extra stress on the back.
• Your job involves lifting, bending or moving heavy objects: lifting badly is a very common cause of back problems at work.
• Your job involves being seated in one place for long periods of time. An unchanging posture can put prolonged abnormal tension on the back.
• Your work involves frequent use of a telephone without a headset. 31% of office workers who use a telephone for at least two hours a day and also use a computer have lower back pain.
• There is a high level of stress, anxiety and tension in your job, or at home. This can generally increase muscle tension throughout the body and increase the chances of a sudden sprain.

Reducing the risk to your back

There is a lot you can do to reduce the risk to your back from your job. Your employer should help you - they may be legally obliged to provide training and appropriate equipment for you or give you regular breaks. But it is also in their interests to keep their workforce healthy - its estimated that each year in the UK 180 million working days are lost due to back problems, costing UK business millions of pounds.

One way to tackle the problem is to apply ergonomic principles to adapt the workplace to suit each specific worker, depending on what their job involves and what their physical make up is. See www.spine-health.com/topics/cd/ergo/ergo01.html. Computer ergonomics, for example, will minimize the risk of repetitive injury, neck strain, lower back pain and leg pain.

Should you stop work if you have a back problem?

There has been a huge change in thinking in recent years about treating back pain. Bed rest, once widely recommended, is now to be avoided. It may be useful in certain cases for 24-48 hours but it can do more harm than good and most people are much better off carrying on with activities as far as possible, although avoiding anything too strenuous.

The box below suggests what you should do when you first develop back pain. The aim is to avoid it becoming a chronic problem. The sooner you are active, the better you will feel and the less likely that you will need to keep taking painkillers. It may seem like an impossible struggle to get back to work but the longer you are off work the lower your chances of ever returning.

Treating an acute back problem

Take things easy but avoid bed rest if at all possible.

If the pain gets worse or you have unusual symptoms such as numbness, pins and needles problems passing urine or pain down the leg, talk to your GP immediately.

Keep as mobile as possible, with gentle exercise (a stroll in the garden, a gentle swim).

Take regular simple pain killers (paracetamol, ibuprofen etc).

Use alternating hot and cold packs on your pack for 15 minutes each, several times a day.

Consider manipulation or other treatments from a physiotherapist, osteopath or chiropractor.

Try to stay working or return to work as soon as possible, even if you still have some pain. If necessary talk to your employer about making temporary changes to your duties to help your recovery.

Keeping your back healthy at work

Improve your general fitness and lose weight if you are overweight.

Take regular exercise, especially to keep the muscles around the spine and abdomen strong and toned so that they act like a corset helping support the back while it does its work. Back Care have some suggestions at www.backcare.org.uk/pages/e_pages/exercise.php.

Wear comfortable clothes, with shoes that cushion your spine especially if you have to stand for long periods. Avoid high heels.

Think about your working environment - is your desk layout or comfortable for your back, and does your chair support the natural S shape of your spine? Avoid getting locked into one prolonged static position. There's detailed advice to help get your workstation right at www.spine-health.com/topics/cd/ergo/ergo03.html.

Make sure you have regular breaks - you shouldn't stay seated in one position for too long and should get up and move around for at least 5-10 minutes every hour.

Work on your posture : you might try the Alexander technique, a set of exercises which can be particularly helpful in reducing the risk of back problems. There is more information at: www.alexandertechnique.com/.

If your job involves lifting or moving heavy weights, your employer should teach you how to lift safely - see www.spine-health.com/topics/cd/ergo/ergo04.html - and provide lifting equipment where appropriate.

TopTips

Learn about your spine and how to look after it. http://www.backcare.org.uk/ are a good resource or try the US government's interactive tutorial at www.nlm.nih.gov/medlineplus/tutorials/backpain/hp129101.html.

Check your working environment - could it be kinder to your back?

If you develop a back problem, try to get back to work as soon as possible.

Carpal Tunnel Syndrome

By Dr Rob Hicks

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.

Prevention is better than a cure, so avoidance of repetitive actions, and taking regular breaks from the activity is essential. If at a computer keyboard, use a suitable wrist support, and make sure the workstation is correctly positioned. Also, check the chair is at the right height.

Anti-inflammatory medicines will relieve the symptoms, and often, experts will recommend the use of wrist splints. If this isn't improving the situation, then steroid injections, or a minor operation to release the nerve compression, is performed.