Khe Vol 5 Siss 1 31to34 [616903]

“Dimitrie Cantemir” Christian University
Knowledge Horizons – Economics
V olume 5, Special Issue 1, pp. 31–34
P-ISSN: 2069-0932, E-ISSN: 2066-1061
© 2013 Pro Universitaria
www.orizonturi.ucdc.ro

Study on Estimating and Decreasing of Visual Stress Level
Caused by the Use of Computers in the Economic Fiel d

Petru BALOGH 1, Pompiliu GOLEA 2, Valentin INCEU 3

1,2,3 Faculty of Tourism and Commercial Management, Constanta , „Dimitrie Cantemir” Christian University, Romania
1E-mail: [anonimizat] , 2E-mail: [anonimizat] , 3E-mail: [anonimizat]

Abstract The in tensive use of computers in office work and its ass ociated stressors, generate mental and
physical demands regarding personnel engaged in thi s activity. This paper aims to assess the most
significant psycho-physiological effects induced in a computer company and to identify direct and
indirect symptoms of visual stress, perceived by st aff working in the video terminals. Also very
important are the organizational measures for the d iminishing of visual stress that must be
implemented by the employers. Finally some simple m ethods are summarized to reduce visual
stress to be reached by every employee. Key words:
Ergonomics, indicators of
visual stress, ways to
combat visual stress

JEL Codes:
O15

1. Introduction
Today information and communication technology is
involved in all areas of human activity and in this
general context, office work is no exception.
Miscellaneous equipment, more sophisticated and
powerful as digital phones, faxes, printers, copier s and
scanners, personal computers and computer networks,
graphics stations, equipment for recording and retr ieval
of information and many others have completely
changed the appearance of traditional offices.
Office work and specific stressors generate intense
mental and physical effects and diseases caused by
them affect the employees in this business.
Therefore call ergonomics is absolutely necessary i n
order to increase productivity, while reducing fati gue
and stress, induced to the employees.
As the International Labour Organization states
"Ergonomics is the application of biological & huma n
sciences, in conjunction with technologies to reach a
mutual accommodation between man and his work,
results being measured in efficiency indices and we ll
being of man." A first step in optimizing the relat ionship
in human)machine)environment system is to identify
and assess the employee requests generated by the
equipment they operate during their current activit y.

2. Some results on the assessment of physiological
stresses arising from computer use
The experienced managers say that most management
problems we face are related to personnel, many of
which are determined by aspects of efficient operat ion in conjunction with providing appropriate working
conditions.
As is revealed in the literature in the context of office
work, misuse of computer generated risks to worker
safety and health. To achieve an ergonomic study on
the subject we consider as necessary the following
steps:
– a set of indicators on psycho)physical effects
induced by the use of computers;
– evaluation based on these indicators of effects
perceived by the questioned staff;
– identify key indicators (those with considerable
weight on questionnaire responses);
– critical analysis of psycho)physical effects and
making recommendations to reduce them.
Using this methodology, such a study was realised o n
staff employed by an independent firm, specialised on
consulting services and online communications
strategy. The company's customers include
organizations and corporations operating in Romania
the market and external market.
The company operates in leased space, divided the
large premises of "open space" for creative and
production departments as well as separate offices for
customer service departments and administrative
personnel. Working hours are 8 h with a lunch brea k of
one hour for administrative, while for production s taff
the program is flexible.

Knowledge Horizons – Economics
Volume 5, Speical Issue 1, pp. 31–34, © 2013 Pro Un iversitaria

32 The set of indicators on psycho)physical stresses
induced by computer use, grouped according to
physiological criteria is as follows:
– eye strain and other eye diseases;
– dizziness, rapid breathing and skin irritation;
– nervous tension, anger, fatigue, depression and
sleep disorders;
– headaches and also neck, arm, shoulder, stomach
and chest pains.
An anonymous character questionnaire was handed to
the administration and production staff of the comp any.
Responses were quantified as a percentage, in relat ion
to the total amount of respondents and represents
stresses received by them due to computer use.

Table 1. Percentage values of indicators on stresses
arising from computer use

No. Indicators Weekly time spent on computer
< 15 h 15 -30 h >30 h
1 Eye strain 27% 34% 58%
2 Headaches 18% 25% 42%
3 Dizziness 2% 7% 6%
4 Sleep disorders 11% 9% 9%
5 Back pains 22% 28% 42%
6 Neck pains 16% 22% 35%
7 Arm pain s 12% 21% 32%
8 Shoulder pains 21% 19% 34%
9 Fatigue 26% 29% 52%
10 Stomach pains 10% 13% 15%
11 Skin irritation 1% 2% 1% No. Indicators Weekly time spent on computer
< 15 h 15 -30 h >30 h
12 Rapid breathing 6% 4% 2%
13 Chest pains 10% 9% 9%
14 Nervous tension 22% 18% 12%
15 Anger 1% 2% 4%
16 Depression 4% 3% 2%
17 Eye diseases 2% 4% 6%

The above data reveal the following:
– the whole extent of perceived personnel stresses
increases with the number of hours spent at the
computer;
– increased frequency indicators are: eye strain,
headaches, back pain, neck pain, arm pain, shoulder
pain, fatigue, stomach pain.
The computer induced stress indicators, from filled in
questioners, having the percentage of at least 10% and
for what the percentage value increases with increa sing
exposure time are presented in the following
histogram.
Questionnaire responses highlight that eyestrain
registers the highest percentage (27%, 34% and 58%
for the three intervals of exposure) between main s tress
indicators and therefore has the greatest influence on
labor productivity. This is the reason further anal ysis will
be dedicated to the manifestations of visual stress
along with some measures to reduce it.
27 34 58
18 25 42
22 28 42
16 22 35
12 21 32
21 19 34
26 29 52
10 13 15
010 20 30 40 50 60 70
<15 h 15-30 h >30 h
Eye srain Headaches Back pains Neck pains Arm pains
Shoulder pains Fatigue Stomach pains

Figure 1 Evolution of main indicators of psycho)physical ef fects, depending of exposure time on the computer

3. Visual stress induced by computer use
As can be seen from the data above, intensive use o f
computer during working hours induces a series of
employee health risks. A first observation is that when
the time spent watching video terminal exceed 30
hours/week, over 50% of users complain eye disorder s.
The most common symptoms of direct visual stress
observed in some studies, are:
– ocular pressure; – look focusing difficulties;
– double image;
– changes in color perception;
– myopia.
Beyond these direct influences on vision system,
scientists have identified some symptoms can includ e
indirect effects such as: fatigue and nervous irrit ability,
low visual efficiency activity, tension and pain in the
neck, shoulders and arms, back pains.

Knowledge Horizons – Economics
Volume 5, Speical Issue 1, pp. 31–34, © 2013 Pro Un iversitaria

33 All this contributes to the registration of common errors
and a low speed range and ultimately lower overall
productivity in office work.
Returning to the question of the impact of computer use
on vision must be stressed that the human visual
apparatus is adapted especially for distance vision .
Over a hundred thousand years, when they were
exclusively hunters and gatherers, but over about t en
thousand years, the main occupation was agriculture
and livestock, people used mainly vision for the re mote
range. Only two centuries ago, when industrial work ers
are becoming the majority in the active population,
human activity became involved in the variable rang e
vision (distant)close)up plan). In the second half of past
century with the increase of employees in office wo rk,
including those working in or adjacent to highly dy namic
field of computer science, has become a necessity t o
accommodate vision to the foreground.
As a result, computer)generated visual stress in of fice
work is an acute physiological imbalance, which the
body is trying to mitigate in a specific way.
For many whom use the computer for a long time (mor e
than 4 hours per day) the most frequent problem is
eyestrain. The latter leads to lower labor producti vity
and also impair the ability to focus on and to well
understand their duties.
Focus vision difficulties are a consequence of iner tia
(backwardness) that the human visual device display s
when we need to accommodate to near vision. The
backwardness depends on the difference between the
distance at which the object is viewed (computer
screen) and natural focus distance of the viewer (w hich
is appreciably higher). Ergonomic comparative resea rch
in visual stress that has been to measure the focal
length of human vision using laser technology, reve aled
that the eyes when watching a video terminal, focus ing
accuracy is lower than if the focus is on a printed page.
On the wide side, another concept used in assessing
visual stress is called "point of relaxation and
accommodation", which is the point where a person's
eyes focus when it lacks the visual field factor ca pable
of giving focused attention. If video terminal is u sed
longer without a break the focal point of the eye m oves
beyond the display and approaching the point of
relaxation, found in distant plan, which degrades
perceived image on the computer screen.
Double image is due to a decrease in the ability to
coordinate eyes, with direct effect on binocular vi sion. It
is a temporary effect but it is useful to consult a n
ophthalmologist, to eliminate the possibility of ot her
serious neurological dysfunction.
Changes in color perception are determined by
constantly monitoring the screen for long periods,
followed by switching the vision on background. Th e
viewer can perceive the opposite or complementary colors that make up the background image on the
screen. Although this may be alarming, it is not
dangerous and disappears after a short time.
Finally, myopia may be caused by improper visual
conditions (low light, the wrong position, permanen t
visual stress), or a genetic inheritance. When it i s not
genetic, myopia may be a poor way to adapt the visu al
device to close plan vision. Studies have revealed that
myopia increases during periods of intense intellec tual
activity and decreases during the rest of visual sy stem.

4. Some measures for the decrease of visual stress
level and effects
So we can see the intensive computer use along the
work program generate risks for the health of
employers. These impose the commercial firms to
follow first the endowments of compartments which
administrate large volumes of dates and information ,
with modern equipments, designed and achieved
according to the ergonomic principles.
Secondly, the executive firm leaders must introduce
some organizational measures for the decrease of
employer visual stress, such as ergonomic design of
work place, suitable furniture or the assurance of the
best office microclimate.
The work places chromatic ambiance and especially
the reflection level for the decorative colors are the
factors that influence the work productivity and ha ve an
important contribution to the visual stress decreas e.
For this point of view it is recommended:
– the choice of a light color, with a reflection coef ficient
greater than 60%, for the ceiling in order to incre ase the
light in the room, and at the same time to prevent the
brilliance;
– the choice of a darker color for the floor, with a
reflection coefficient about 15)30%;
– the choice of a lighter color for the furniture, wi th a
reflection coefficient between 30% and 50%;
– the choice of neutral colors for computer equipment s
(gray or beige).
The office furniture for computer operators place m ust
achieve a balanced report between comfort and
functionality, and for that it is necessarily:
– adjustable chairs in height with adjustable chair
back;
– supports for legs;
– supports for computer screens with adjustable arms
in order to establish the position of screen center under
the eyes level and to eliminate parasite reflection s;
– supports for documents with adjustable arms;
– mobile supports for keyboards.
The physical ambiance of the work place includes
factors such light, temperature, humidity and noise
levels that must respond to specific office equipme nt
solicitations, as bellow:

Knowledge Horizons – Economics
Volume 5, Speical Issue 1, pp. 31–34, © 2013 Pro Un iversitaria

34 – a light level for the computer operator offices abo ut
400)500 lx (for general purpose offices the
recommended value is about 800)1000 lx);
– a temperature of 21)23 Celsius degrees,
recommended for intellectual work in a seating posi tion;
– a difference between outside and inside temperature s
in the warm season not greater than 4 Celsius degre es;
– a relative air humidity level of 70% at a temperatu re of
22 Celsius degrees;
– a maximum noise level of 70 db (the phone ring
sound intensity is 75 db).
In addition with the ergonomic computer design and
implementing organizational protection measures the re
are others simple ways to reduce visual stress to r each
by every employee, practicing in front of a video
terminal.
Blinking is a reflex act of vision device that allo ws the
eye to rest for a few fractions of seconds and help s
clean and moisten the eye surface. Normally, a pers on
blinks about 15 times per minute. Blinking rate is
reduced when effort is strong and lasting through t he
eyes focus on details of the near plan vision. So a fter
these times of maximum concentration is highly
recommended voluntary blinking repeated until no
sensation of eye irritation.
On the other hand, when we are extremely focused on
work we tend to hold our breath, which causes
involuntary contraction of muscle groups, including the
composition of the visual apparatus. Maintaining a
normal rate of respiration provides relaxation of t hese
muscles, and helps reduce muscle tension even at ey e
level. In addition to reducing visual stress accumu lated
by using the computer, the human body needs breaks
to relax eyes. For example, from 10 to 10 minutes
during 10 seconds is recommended to focus the visio n
on a point in the background, blinking and breathin g
normally.

5. Final remarks
Ergonomic study conducted in a computer service
organization has allowed detection of the most
significant physiological effects, based on an exte nsive
list of indicators of psycho)physical effects cause d by
computer use.
On this basis, were identified a series of direct a nd
indirect symptoms of visual stress, perceived by st aff
working in the video terminals.
A computer's operating business with over 30
hours/week, for which humans are not biologically
adapted, is able to determine a range of visual
problems.
However, the importance of computer use in economic
activities is undeniable. So, the technical and
organizational measures to reduce the visual stress levels, which must be implemented by the employers,
are of great importance.
Finally were summarized also some simple methods to
reduce visual stress, available to every employee.

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