Protection From Computers_1

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Protection From Computers: Do The Eyes Have It?

More and more Australian workers spend some of their work hours in front ofa computer screen. Paul Somerville reports on current thinking about whetherscreen-based work poses a serious threat to the eyes.

Few would dispute that good vision is one of the most important aspects ofgood health and wellbeing. Sight is arguably the most vital of the senses, bothfor eperiencing the world and participating within it.

For those of us who are sighted, it is hard to imagine a waking hour, or evenmoment when we don!t depend on our eyes for essential information, "heyguide our decisions from moment to moment. #n our occupations, our eyesare critical. $hatever our industry or %ob position, sight is important for mosttasks in most %obs.

All this may seem perfectly obvious, but #!m labouring the point in order tocontrast the fundamental importance of eyesight with the blase attitude to eyeprotection that eists in some workplaces.

#n Australia, eye in%uries are by no means rare at work. According to $orkSafe$A, for eample, about & per cent of all lost-time in%uries in $estern Australiainvolve eyes. #n the metal products manufacturing industry, this figure is morethan '( per cent.

Computer screens

)ne instance in which eye protection is often not carefully considered is in theuse of computer screens and the effects they might have on vision. "he factthat this is often overlooked is surprising, given the large numbers ofemployees who spend a significant proportion of their working lives in front ofcomputer screens.

"he A*"+ released a set of detailed guidelines for any work involving screen-based euipment in /. "he guidelines claimed that visual problemsincluding fatigue and problems with contact lenses were one of the mainha0ards associated with the use computers.

"he guide suggests employers should limit the total time employees spentdoing screen-based work and the length of continuous periods at such work,so that !employees are not reuired to spend more than half their ordinaryhours of work on any day performing screen-based work!. #n the case ofworkers who do concentrated work in front of computer terminals, the guiderecommends taking regular breaks of at least 1 minutes in every hour.

Sue Pennicuik, )2S unit co-ordinator for the A*"+, told Australian Safety thatshe recently came across information about protective glasses for peopleworking at computer screen. !)f course, the A*"+!s view is that if your eyes

are that sore, you shouldn!t be in front of the screen in the first place,! shesays.

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!#t is our view that work should be reorganised, such that people are not sittingin front of computers for long enough periods so that their eyes become soreor strained. "his is not a popular view, because many people think thatemployees should spend si or eight hours of each day in front of a computerscreen,! Pennicuik says.

Frank 3arby, ergonomist currently working with the 4ictorian $ork*overAuthority, did a lot of policy work on the safe use of visual display units543+s6 when he worked in 7ew 8ealand for that country!s government healthand safety authority.

3arby uses the phrase !visual and ocular discomfort! to incorporate all thefamiliar complaints to do with eyes and computer use, including eye strain,sore eyes, dry eyes and headaches.

!"he vision system comprises the eye, the muscles controlling the eye, the

head that supports the eye socket, the upper parts of body supporting thehead and visual processing centres in the brain.

!4isual and ocular discomfort in people using 43+ screens is largely causedby looking in same direction and at the same focal point for a long time. #netreme circumstances, this creates back and muscle strain, but theimmediate area of eyes is the first to be affected,! he says.

3arby says that although there is little direct statistical information on thefreuency of this condition, some say visual and ocular discomfort associatedwith computer use is very common. !"he +9 2ealth and Safety :ecutive hasscreen regulations which say that any computer user who asks their employerfor an eye test must be given one. "his is because the 2S: feels thatabsence from work from visual discomfort is common, and the costs ofproviding testing will outweigh by ( to one the costs of visual discomfortdeveloping,! he says.

3r Stephen 3ain, head of the School of )ptometry at the +niversity of 7S$,agrees that while there are no proven long-term effects on the eyes of usingscreen-based euipment, the common complaints from computer users abouteye fatigue need to be effectively managed by workplaces.

3ain has been involved in researching the impact of use on the eyes foryears, ever since the school did the first longitudinal study in the world on thesub%ect for "elstra 5then "elecom6. "he study was of "elecom data-entryoperators who had %ust started using screen-based euipment rather thanstandard telephone directories. #nterestingly, it revealed that the change waspositive for employees eye condition. !#t was a conseuence of removal ofsomething that was more demanding for the eyes.!

The real danger

3ain also debunks the oft-heard myths about +4 rays and the !bogey ofradiation! in relation to computer use. #n both cases, he says that the amounts

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involved are well below any perceived risk to occupational safety standards.!2earing people talking about the dangers of these things makes me uiteangry,! he says, !because it is unnecessarily creating industrial stress.!

"he only real danger to the eyes associated with computer use, according to

3ain, is !eye strain! 5a term 3ain admits is misleading6 technically known!asthenopia!. Although he says this cannot cause permanent damage to theeyes, it is a significant )2S problem, affecting up to ;( per cent of those whouse computers in their work.

!)ur research has not turned up anything clear which predisposes someone tosuffering symptoms of eye fatigue. "he number one factor in someonesuffering visual symptoms is how much stress the sufferer is eperiencing."he other thing to note is that symptom reporting is age-related. People whoare older tend to complain less of visual discomfort,! he says.

!:ye strain is really a misleading term for what we are talking about, becauseit suggests physical damage, which it is not. #t!s a symptom that representssub%ective fatigue, not a symptom of damage. After a day at the computer, anemployee!s eyes may feel terrible, but the net day they will be okay again,!3ain says.

!So there is no physical damage, but that doesn!t mean there aren!t a lot ofpeople having a lot of problems that workplaces must address. Fororganisations wanting to minimise visual and ocular discomfort, there are arange of issues to consider.!

"he first problem he cites is dryness of the eyes. !$hen you do sustainedwork you tend to blink less and this is an even greater problem with computerwork because it is always ready to go< there are no pages to turn or breaksreuired. "he humidity in an airconditioned office eacerbates the problemand the tear film over the eye can dry out. )ne solution is to get the screen toblank every few moments as a reminder to blink. "aking breaks, as with anyrepetitive work, is also vital.

!#t is important that people follow the standards to do with ergonomics, lighting,screen colour and so on,! 3ain says, although this will not correct all eye

fatigue problems. !#n the "elecom research, the ergonomics were right, but still'1 per cent of the employees had visual discomfort symptoms. #t wasconcerning to note that many of those same employees had not had eyeschecked in past two years,! he says.

"he relevant standard on screen-based euipment is AS =1(. Part # isfocused on the screen, Part ## on the workstation and Part ### on the inputdevices.

!>lare can be corrected with !guards! or anti-reflection coating, but in manycases, problems of screen glare can be corrected by lighting and avoiding

windows,! 3ain adds.

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So aside from taking breaks, following standards and correcting workstationand office design, what can people do to prevent eye fatigue at the computer?

!$e notice that people are still getting a computer and placing it on their olddesk in a traditional office environment. "he problem is that the height of the

deck you need for writing is different to the height reuired for a keyboard. #nthis respect, laptops are a problem, because they attach the screen to thekeyboard, when they need to be at different heights for ergonomic reasons. #naddition, people are all different heights, which needs to be taken into accountas well,! 3ain says.

Prevention

According to Frank 3arby, there are reuirements for preventing visual andocular discomfort@ first, get the ergonomics right< second, make sure theperson!s !visual apparatus! 5eyes plus any glasses needed6 is operating

correctly< and finally, make sure that periods of work are followed by periodsof non-work.

>etting the ergonomics right involves ensuring that the image pro%ected by thecomputer screen is of good uality, not flickering or otherwise unstable andthat there is no glare or reflections on the 43+ which makes the image hardto see. #t also includes taking steps to ensure that your head is not held stillfor very long periods of time.

:nsuring !visual apparatus! is operating correctly means a visit to anoptometrist. 5)f the three sorts of professionals in this area, opticiansoptometrists, ophthalmologists, 3arby says optometrists are most appropriatebecause they assess the light-handling ualities of the eyes and also look fordisease6.

3arby says that the need to break periods from work with periods of non-workwas epressed well by the #talian physician ernardino Bama00ini, who statedabout the problems of sore arms developed by the uill-using scribes andnotaries of his day@ !ut what troubles these workers the most acutely is theintense and incessant application of the mind, for in work such as this, thewhole brain, its nerves and fibres must be kept constantly on the stretch.!

!"here is nothing new under the sun,! 3arby says. !43+ use tends to go intoprolonged periods of work 5without us realising6 and after a few hours wesuddenly realise we!re hurting. #f 43+ use is intense and prolonged, then wisemanagers will make sure people have the opportunity to, and do, takeadeuate breaks.!

3arby says that screen flickering is an issue for the eye comfort of those whowork in front of computer screens, but will become less so in future. !#t!s stillthe case that most screens still flicker at ;( hert0 a freuency at which mostpeople!s vision is affected. At /1 20, people are much more likely to avoid

discomfort, and computers are moving towards this freuency. "he flat paneldisplays on top of laptops do not flicker at all and have a better resolution, so

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we are likely to see an decrease in visual discomfort from screen flickering inthe future,! 3arby says.

3on!t waste energy worrying about urban myths related to the risks ofcomputer use. "here are enough real risks to worry about. 3esigning work so

that regular breaks are factored in and the ergonomic issues are considered isthe best way to tackle the prevalent )2S problem of visual and oculardiscomfort caused by screen-based euipment.

Source: National Safety Council Of Autralia's Australian Safe

Computer Workstations

Chair

A properly designed and ad%usted chair will provide appropriate support to the

back, legs, buttocks and arms. "his support can reduce contact stress, overeertion and fatigue. #t will also promote proper circulation to the etremities."he following items are critical to an employee who spends etended hours atthe workstation@

Seat Position *hair 2eight

Armrest

"he proper ad%ustment of the chair is related to the proper placement of the

monitor, keyboard, mouse and work surface.

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onitor and Document

Monitor and document placement is important in creating a comfortable

workstation. *onsider the following items in order to reduce awkward headand neck postures, fatigue andCor headaches@

3isplay Source 3ocument Position

"he monitor and document are related to the placement of the keyboard,mouse, and properly ad%usted chair.

!ey"oard and ouse

"he proper position of the keyboard and mouse is essential in creating acomfortable workstation. *onsideration of the following factors can helpprevent musculoskeletal disorders such as carpal tunnel syndrome andtendonitis@

2eight and )rientation

Placement 3esign and +se

Source: OSHA. USA

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Computer Workstations # Chair

$eat Position

Potential Ha%ard:

#mproper si0e, shape, or choice of materials for the seatpan and backrest may result inuneven weight distribution, contact stress, decreased circulation to the etremities andawkward posture.

Possi"le $olutions:

"he seat and backrest of the

chair should support acomfortable posture that allowsfreuent changing of theseating position 5Fig. 6.

Fig& '(d)usta"le chair and "ackrest&

$eatpan *ith a rounded+,*ater-all, edge&

"he seatpan should accommodate the specific employee 5not too bigCsmall6. #t should be

padded and have a rounded, DwaterfallD edge 5Fig. 6. "his will reduce contact stress to theback of the legs.

"he angle of the seatpan is also important. A seatpan with an ad%ustable tilt ensures the

worker is able to maintain proper support in different positions.

Chair Height

Potential Ha%ard:

#mproper chair height.

Possi"le $olutions:

*hairs should be height ad%ustable, especially in work areas where they are shared by a

number of employees.

"he chair height is correct when the entire sole of the foot

can rest on the floor or a footrest 5Fig. '6, and the back ofthe knee is slightly higher than the seat of the chair 5Fig.=6. "his position allows blood to circulate freely in the legsand feet.

Fig& . Footrest&

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Fig& / !nee slightly higherthan the seat o- the chair&

(rmrest

Potential Ha%ard:

Armrests that are too high or too low can produce awkward postures, create contact stress to

the elbow, provide inadeuate support, and may prevent the operator from moving closeenough to the workstation.

Possi"le $olutions:

Ad%ustable armrests 5Fig. E6 can be lowered to fit under worksurfaces. "his allows the user to work from a comfortabledistance.

"he armrests should support both forearms while the

employee performs tasks and should not interfere withmovement.

Fig& 01--ice chair *ith

ad)usta"le armrests&

2elated (rti

Computer Workstations # onitor 3 Document

Display

Potential Ha%ard:

A display screen that is too

high, too low, or placed to theside of the user 5Fig. 6, may,over time, cause awkwardpostures and increased stresson the muscles of the neck,shoulders, and upper back.

Fig& 'Display screen too lo*&

Possi"le $olutions:

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9eep monitor directly in front of

the user.

"he topmost line of the screen

should not be higher than theuser!s eyes.

Screens that swivel hori0ontallyand tilt or elevate verticallyenable the operator to select acomfortable viewing angle5Fig. '6.

>enerally, placing the monitor

on top of the computer will raiseit too high.

Fig& .Com-orta"le vie*ing angle&

Potential Ha%ard:

"ilting the head back to read through the bottom portion of bifocal lenses can stress theneck, back and shoulders.

Possi"le $olution:

"ilting of the head can be avoided by lowering the display or using single-lens glasses with a

shorter focal length while viewing the monitor.

Potential Ha%ard:

4iewing distances that are too long or too short can cause stress and eye strain.

Possi"le $olutions:

"he preferred viewing distance

is / to 'E inches. #f there is notenough table depth toaccommodate this distance,install a keyboard etender ortray underneath the desk 5Fig.=6.

"he table depth should

generally be at least =( inchesfrom the wall to properly

accommodate monitors.

Pull tables and desks away

from the wall and dividers toprovide more space formonitors.

Fig& /Pre-erred vie*ing distance&

Potential Ha%ard:

4iewing the monitor for long periods of time can cause eye fatigue and dryness.

Possi"le $olutions:

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Best eyes periodically by focusing on an ob%ect at least '( feet away.

Stop, look away, blink andCor stretch at regular intervals.

:pand the employee!s duties with other non-computer tasks such as filing, phone work, orcustomer interaction to provide periods of rest for the eyes.

$ource Document Position

Potential Ha%ard:

Awkward posture or freuent movement of the head and neck to look from the monitor to a

document.

Possi"le $olution:

"he screen and document holder

should be close enough together so theoperator can look from one to the otherwithout ecessive movement of thehead, neck or back 5Fig. E6.

Fig& 0$creen and document holder are

close

together and same distance -rom theeye&

#f writing needs to be performed, a

document holder can be positioneddirectly beneath the monitor5Fig. 16. "his provides a sturdy writingsurface and prevents freuentmovement of the head, neck or back.

Fig& 4In#line document holderthat allo*s -or *riting&

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Computer Workstations # !ey"oard 3 ouse

Height and 1rientation

Potential Ha%ard:

#mproper height and angle of the keyboard, mouse, or working surface can cause employees to bend theirtheir arms for etended periods.

Possi"le $olutions:

"he work surface may need to be raised or

lowered to keep the operator!s arms in acomfortable position. "his can be achieved byinstalling an ad%ustable keyboard etender or tray5Fig. 6, by providing an ad%ustable tableCworkingsurface, or by raising the chair and providing afootrest if needed. Fig& ' !ey"oard tray&

Ad%ust the keyboard andCor chair height so the employee!s elbows can hang comfortably at the side of the

shoulders are relaed and the wrist is not bent up or down or to either side during keyboard use 5Fig. 6.

"he angle of the keyboard should also be considered when determining the preferred height. "he preferre

position for most keyboard operators is with the forearms parallel to the floor and elbows at the sides< thishands to move easily over the keyboard.

Placement

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Potential Ha%ard:

A keyboard or mouse that is not directly in front of or close to the body 5Fig. '6 forces the

employee to repeatedly reach during use.

Fig& . ouse placed too -ar

-rom the "ody&

Fig& / ouse placedclose to the "ody&

Possi"le $olutions:

Make sure the keyboard is placed directly in front of the user.

"he mouse should be positioned at the operator!s side with his or her arm close to the body

5Fig. =6. A straight line should be maintained between the hand and the forearm. "he upperarm should not be elevated or etended while using the mouse. "he employee should nothave to reach to use the mouse.

*onsider using a mouse platform that

rotates above the keyboard whilemaintaining about the same plane."his design 5Fig. E6 allows the mouse

to be used above the (-key pad,which gives the user a better wristangle and reduces reach.

Fig& 02otating mouse plat-orm&

Design and 5se

Potential Ha%ard:

ending wrists sideways 5Fig. 6 or up and down 5Fig. '6

while keying.

Fig& . 6ending the *rist up*ard&

Fig& ' Ha%ardous side"ending o- the *rist&

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Possi"le $olutions:

Beduce bending of the wrists by moving the entire arm.

3o not use the feet provided on the back of most keyboards if this causes wrists to bend upward 5Fig. '6.

lower in relation to the keyboard, the keyboard feet may be used to maintain a neutral wrist 5Fig. =6.

Fig& / $traight *rists *ith a rest&

$rists should be etended straight, not

bent up or down. A mouse pad or wristrest can be used to help maintain straightwrists. $ristCpalm rests 5Fig. =6 should notbe used while keying, but to rest thewrists between periods of keying.

*onsider using alternative pointing devices such as

trackballs 5Fig. E6, or touch pads.Alternative keyboards5Fig. 1,;6 may also be helpful in allowing the worker tomaintain a neutral wrist position.

Fig& 0 Track"all&

Fig& 4 Fig& 7

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