Effects of Frequent Usage ofComputer to a Person’s Eyesight
aElsevier Science S.A. , PO Box 564, 1001 Lausanne, SwitzerlandbEconomics Department, University of Winchester, 2 Finch Road,Winchester, Hampshire P3L T19, UK
Received 1 March 2000 accepted15 March 2000
Inthe contemporary workplaces and educational contexts, peopleincreasingly adopt computers in their daily operations. However, thesituation has raised several health concerns, one of them beingvision problems. Many individuals whose works involve computers havereported higher levels of job-related complaints such as muscularstrain, discomfort, and stress (Price & Richard, 2009). The levelof these concerns increases with an individual’s level of exposureto computers. Visual discomfort and other visual related symptomscaused by frequent exposure to computers must be recognized as one ofthe growing health problems. The term Computer Vision Syndrome (CVS)has been coined to refer to vision problems related to frequent usageof computer (AOA, 2013). Many people who work with computers everydayexperience either eye-related discomfort or visual health problems.Nevertheless, based on the current evidence, it is important to notethat frequent use of computer is unlikely to cause permanent healthproblems for the user’s eyes.
In the contemporary workplaces and educational contexts, people increasingly adopt computers in their daily operations. However, the situation has raised several health concerns, one of them being vision problems. Many individuals whose works involve computers have reported higher levels of job-related complaints such as muscular strain, discomfort, and stress (Price & Richard, 2009). The level of these concerns increases with an individual’s level of exposure to computers. Visual discomfort and other visual related symptoms caused by frequent exposure to computers must be recognized as one of the growing health problems. The term Computer Vision Syndrome (CVS) has been coined to refer to vision problems related to frequent usage of computer (AOA, 2013). Many people who work with computers everyday experience either eye-related discomfort or visual health problems. Nevertheless, based on the current evidence, it is important to note that frequent use of computer is unlikely to cause permanent health problems for the user’s eyes (Torrey, 2003). In this literature review, we are going to review journal articles about computer usage related eye problems and their recommendation to prevent or reduce eye problems related to computer exposure.
According to Graney (2011), majority of workers who use computers to do their works often experience eyesight problems. Nevertheless, it is still unclear to which extent these eyesight problems occur in computer-based environment compared to other visual demanding work contexts. According to the survey conducted by the United States optometry doctors, more than 14 percent of their patients have eyesight problems, which are linked to frequent usage of computers. According to Watt (2003), the most common symptoms of eyesight problems caused by exposure to computers include blurred vision, eyestrain, headache as well as shoulder and neck pains. The level at which an individual might present with these symptoms high depends on the person’s visual ability concerning the visual demands of the task he or she performs. However, it is important to note that these vision health concerns are neither unique nor new to computer use. Majority of people working in environments with high visual demands will experience the same vision related problems.
The unique aspects and high visual demands in computer based work contexts make many people vulnerable to the development of eyesight problems. According to Torrey (2003), uncorrected vision conditions, workplace ergonomics, poor computer design, and high visual demanding tasks are the main contributors to the development of eyesight problems and complaints. Many vision problems Computer operators experience are only temporary. When one stops using the computer frequently, the eyesight conditions decline (AOA, 2013). Nevertheless, depending on an individual, some people would have continued impaired vision such as blurred vision after they have stopped frequent use of computers. In such cases, medical intervention is essential because some of the situations may recur or worsen in the future as one continues to expose his or her eyesight to computer screen (Watt, 2003). Working conditions that involve visual and physical fatigue often lead to reduced productivity, increased errors, and could potentially develop stress and discomfort.
Visual Demands of Computer Usage
Looking at the screen of a computer is different from looking at printed or typewritten pages. Letters in on the screen a computer are often characterized sharp characteristics, reduced level of contrast of letters to the background, reflection, and the presence of glare on the screenSmita, Goel and Sharma, 2013). These aspects makes it more difficult more difficult to view the letter as many viewers often strain their eyes in the process of viewing to establish meaning out of them. The viewing distances and angles by computer operators are unique compared to those involved in reading and writing in a normal paper (Schlossberg et al., 2004). The requirement of eye focus and movement by computers involves additional demand, which leads to straining one’s visual system. An individual who is used to the physical paperwork may find it difficult to adjust computer usage, and can suffer serious eyesight problems within a short period of exposure.
Even though people with eyesight problems under normal situations have been using eyeglasses and contact lenses prescribed by their opticians, it is important to note that these devices are inadequate when it comes to reducing or preventing computer-based vision problems (Bali, Navin and Thakur, 2007). However, there are specific lenses prescribed for computer operator. These lenses have special design and power to enhance maximum visual ability and comfort when a person uses a computer. This is important because there are people whose livelihood and that of their families depend on computer-based occupation, which is also their profession. With the special glasses, the quality of worker’s vision and their productivity has improved. In addition, other people may require optometric vision therapy, which is designed for the treatment of binocular dysfunctions caused by frequent exposure to the computer screen (Shrestha, Mohamed & Shah, 2011).
Several preventative measures that one can take to reduce the visual strain and stress caused by long time exposure to computer are available. According to Alexandre and Milano (2006), one can rest or alternate tasks within the workplace throughout the day. It is important to note that many computer related tasks are often repetitive and may lead to both mental and physical instability, especially when an individual work for an extended period. Sometimes, having rest or changing tasks help in fighting the visual fatigue and strain. It helps the computer operator to incorporate other tasks, which are less visually demanding like looking at the computer screen (Alexandre & Milano, 2006). Nevertheless, this should be based on the person’s visual needs and the extent of visual negative reaction to computer screens. It is because the visual problems often differ from one person to another. People who already have vision problems are more vulnerable compared to those who are visually fit.
Pre-existing Vision Problems
People with pre-existing eyesight problems, even if it is a minor problem may experience significant effects of long time computer exposure. Some of the pre-existing vision problems may include short-sightedness, long-sightedness, presbyopia, and binocular vision, which relates to the coordination and focusing of the eye (Price & Richard, 2009). A person who had these problems before frequent exposure can often demonstrate eye-related problems. Higher percentages of computer operator with pre-existing vision condition have been found to be suffering a great deal of visual comforts and poor performance. Although some of these pre-existing problems might not result into symptoms related to visually demanding conditions, high demand of visual attention when using computer to a perform tasks may make them manifest. Therefore, a comprehensive eye examination is essential for those who intend to use computers for the major part of their career (Shrestha, Mohamed & Shah, 2011).
Just like many electronic devices, computers emit radiations when they are switched on, and operators use them to perform tasks. These radiations include infrared rays, visible light, radiofrequency emissions, x-rays and ultraviolet rays. Nevertheless, emissions of these radiations by computers are so low to an extent that they fall below the recommended safety levels. Several studies such as a study by Bali, Navin and Thakur (2007) have been conducted in order to determine if there is any effects these radiations emitted from computers can cause to their operators. However, repeated studies have not shown any association between using computer and radiation, and eyesight problems. For instance, no study evidence has proved that radiations from computers contribute to the development of cataracts. Nevertheless, many computers often develop an electrostatic charge within the screen’s periphery as it operates. These static charges often cause attraction and accumulation of airborne particles and dusts onto the surface of the computer’s screen. Even though there is no conclusive evidence about their effects, these static charges may have been one of the major contributors to eye irritation among hypersensitive individuals (Smita, Goel and Sharma, 2013). Cleaning computer regularly is enough to manage this problem.
Dry Eyes and Eye Redness
Having a dry eye is a symptom of computer vision system. It is important to note that the dry eye in this context is different from the one that is common with elderly people. It has been discovered that the rate at which one’s eyes blink may reduce by approximately 60 percent if the person sits for a long time at the computer monitor (Smita, Goel and Sharma, 2013). As a result, reduced rate of blinking often contributes to reduced production of tears, which is the main cause of dye eyes. This condition temporarily strains the cornea, making the eyes dry up (Bhandeni, Choundhary & Doshi, 2008). This depicts dry eyes as the one of the main eye problems those who work with computer for a long time experience. On the other hand, eye redness, which is a symptom of computer vision system, is prevalent among computer users. About 40 percent of computer users suffer eye redness.
Experiment on the Computer Screen Usage on Human Eyesight
To decide the rate at which participants` eyes were breaking down because of intemperate use of computer screens, an investigation was done on four different groups with homogenous demographic characteristics. The subjects included were participants with distinctive levels as far as hours of computer screen use are concerned. The main objective of the experiment was to establish whether there is a closer relationship between the length of computer screen use and the effects of blurred eyesight and dry eyes.
The experiment included five basic inquiries that created the hypotheses and developed the variables tested.
a) What is your average usage of continuous computer screen usage?
b) Do you experience dry eyes?
c) Do you have issues with blurred eyesight after using computer screen?
d) Do you experience dry eyes and blurred eyesight after using computer screen?
e) Do you have eye problems?
The first question was asked to all participants before one other question was asked from the remaining four. Four different sites were used by the four different experimenters. The shopping mall pack yard was one of the sites used for the experiment. A public park formed another site for the experiment. The exit to a café was selected for its suitability with many willing participants with some time to spare for the experiment. The walkway became site for the last experiment. The inquiries were chosen all things considered on the grounds that these are the side effects of dangerous eyes influenced by the light transmitted by the computer screen. The recurrence of the bothersome disturbance was additionally considered regarding whether it happened regularly or once in a while. The sort of eye help paid special mind to be exhibitions, contact lenses, and shades.
To complete this trial, four experimenters were utilized, two women and two gentlemen. They were to approach participants randomly in the road outside an occupied shopping centre different parks and question participants of diverse gender and age. These experimenters had some optical units with them in the event that the subjects of the investigation did not know about whether they could see obviously. These had a few large boards printed with numbers of diverse sizes but similar colour. The experimenter would hold the board towards the subject and request that they make out the numbers on the boards at short proximity. At that point they would move away at distinctive separations and solicitation the subjects to peruse an alternate board with diverse numbers of distinctive sizes. The separation at which the subject neglected to make out the accurate numbers or began to see hazy pictures was checked against the normal separation of sight of a man of their estimated age with great visual perception. In the event that the separations were about the same, then the subject had great visual ability.
Boards with diverse printed numbers were utilized to maintain a strategic distance from the memory impact on the subjects. In the wake of seeing a letter, it is anything but difficult to make it out again even without seeing it plainly. To maintain a strategic distance from this mix-up in the test, distinctive prints were utilized.
Null Hypotheses = Lengthy computer screen usage does not leads to dry eyes
Researcher Hypotheses = Lengthy computer screen usage leads to dry eyes
Null Hypotheses = Lengthy computer screen usage does not leads to blurred eyesight
Researcher Hypotheses = Lengthy computer screen usage leads to blurred eyesight
Null Hypotheses = Lengthy computer screen usage does not leads to dry eyes and blurred eyesight
Researcher Hypotheses = Lengthy computer screen usage leads to dry eyes and blurred eyesight
Null Hypotheses = Lengthy computer screen usage does not leads to eye problems
Researcher Hypotheses = Lengthy computer screen usage leads to eye problems
Participants from distinctive gender were utilized in spite of the fact that the information was later sifted into the quantity of computer screen hours one uses for each day. To get the information that was to be broke down to Chart out if the theory was invalid or should have been be dropped, a specimen must be resolved. A randomized test succession was favoured in light of the fact that there is no particular gathering of participants with the same sort of optical hindrance. It was favoured that a youthful age gathering be utilized. It was a direct result of the impact of age on vision. Utilizing an example of the more established age gatherings would realize deception since long-sightedness is basic in old participants paying little respect to whether they utilize computer screens or not. A specimen size of 10 members for each scope of hours was regarded fitting for the analysis for dependable results. The scope of hours was chosen as 9, 8, 7, 6, 5, 4, 3, 2, 1 and under 1 hour for each day. Considering these 10-hour sections, the aggregate targeted members were 100, and every experimenter was to approach and explore a normal of 25 members.
Counsel was given to the participants who required some advice. Any inquiries they had would likewise be replied by the experimenters. It was favoured that the members be asked whether they were willing to take an interest in the brief test, after which it would be disclosed to them the motivation behind the examination. On the off chance that there was a respondent with totally blurred eyesight and did not recognize what to do, they would be requested that visit the closest opticians. A few boards on legitimate eye consideration were likewise issued to the members who volunteered to answer our inquiries. The speculation was very proper for this test and the mode with which it was tried was certain to yield great results.
The information gathered was recorded in tables demonstrating the scope of hours and normal hours utilized as a part of front of a working computer screen. The quantity of the influenced members was likewise recorded per scope of hours. The quantity of participants was additionally isolated into gatherings as those with dry eyes, those with blurred eyesight, participants with healthy eyes and those with both dry eyes and blurred eyesight.
The information gathered was as in the table underneath:
Daily usage Dry eyes Blurred eyesight Blurred eyesight & Dry eyes Healthy eyes
9 1 4 2 1
8 2 3 2 1
7 6 2 3 2
6 4 2 2 0
5 4 1 2 2
4 3 2 3 1
3 2 3 4 6
2 2 1 2 2
1 1 0 1 8
Table 1: Data gathered
From the table above, it is obvious that the quantity of participants influenced by both blurred eyesight and dry eyes increments as the normal hours every day increments. The inverse is valid for the quantity of participants not influenced. Their number is most elevated for the hour section of under two hours for every day and zero for the high hour sections. Information from the table is measurably dissected to give different results.
The clear investigation of the diverse eye imperfections in connection to the quantity of hours the subjects are presented to light from a computer screen is performed. The outcomes are as demonstrated as follows:
Daily hours, Dry eyes, Blurred eyes, Blurred eyes & Dry eyes, Healthy
Variable Mean SE Mean StDev Minimum Median Q3 Maximum
Daily hours usage5.000 0.913 2.739 1.0005.000 7.500 9.000
Dry eyes2.778 0.547 1.641 1.0002.000 4.000 6.000
Blurred eyesight 2.000 0.408 1.225 0.0002.000 3.000 4.000
Blurred eyesight & Dry e 2.333 0.289 0.866 1.0002.000 3.000 4.000
Healthy 2.556 0.884 2.651 0.0002.000 4.000 8.000
The two eye imperfections are contrasted with the hours behind the computer screen in a correlation to give the yield demonstrated as follows:
Correlation: Daily hours usage, Blurred eyesight & Dry eyes
Pearson correlation of Daily hours usage and Blurred eyesight & Dry eyes = 0.053
P-Value = 0.893
Correlation: Daily hours usage, Healthy
Pearson correlation of Daily hours usage and Healthy = -0.689
P-Value = 0.040
It can be watched that the P-value for the two connections varies, demonstrating a shifting relationship between those influenced and those not influenced by light from a computer screen. The variety is achieved by the quantity of hours every individual needs to sit before a computer screen.
The connection between presentation to light from a computer screen and its impacts on the human eyes can likewise be found in a regression analysis of measurements. By the utilization of Minitab, the relapse model can be created to show the fluctuation and regression error. It is appeared in the handled data beneath:
Regression Analysis: Daily hours usage versus Blurred eyesight & Dry eyes
The regression equation is
Daily hours usage = 4.611 + 0.167 Blurred eyesight & Dry eyes
S = 2.92363R-Sq = 0.3%R-Sq(adj) = 0.0%
Analysis of Variance
SourceDF SS MS FP
Regression10.1667 0.16667 0.02 0.893
Error 7 59.8333 8.54762
Total 8 60.0000
The above is the regression analysis of normal computer screen hours every day versus both dry eyes and blurred eyesight.
The following is the regression analysis of normal computer screen every day versus the participants who are not influenced by light as a consequence of practically zero introductions by any stretch of the imagination:
Regression Analysis: Daily hours usage versus Healthy
The regression equation is
Daily hours usage = 6.818 – 0.7115 Healthy
S = 2.12272R-Sq = 47.4%R-Sq(adj) = 39.9%
Analysis of Variance
SourceDF SS MS FP
Regression1 28.4585 28.4585 6.32 0.040
Error 7 31.54154.5059
Total 8 60.0000
To get an unmistakable and complete perspective of the regression analysis (Thomas, 2011), residual plots of computer screen time versus those with both dry eyes and blurred eyesight and computer screen time versus those not influenced are made. The relationship is visualized in the graphical below
Chart 1: Residual plots for dry eyes and blurred eyesight.
Chart 2: Residual plot for those healthy
The remaining plots give an examination of various types of plots, among them box plots and inclines. The correlation is helpful in metaphorically clarifying the variety of eye issues among participants of shifting hour bunches. It is apparent from the diagrams that the more extended the time one works before a computer screen with negligible or no light shield by any stretch of the imagination, the more they are prone to wind up having eye aggravations and imperfections.
To stress on this, a plot looking at normal hours every day and the quantity of participants influenced was finished.
Chart 3: Average hours versus number with both dry eyes and poor vision
The line of the ideal fit is a reasonable sign that there is for sure an immediate relationship between the quantity of hours one is presented to light to the impact this has to their eyes. From the chart, participants with fewer than two hours are seldom influenced while those with nine hours of presentation are profoundly influenced and bothered by their eyes. The discoveries are underscored by an individual worth plot.
Chart 4: Individual worth plot for the diverse impacts of introduction
From the individual worth plot, it can be seen that lion`s share of great importance sections have zero as the quantity of the general population not influenced, one for those with blurred eyesight, two for those with dry eyes just and six for those with both blurred eyesight & dry eyes. It demonstrates that most of the subjects of the investigation had one or more eye imperfection brought about by dealing with a computer screen for a really long time.
At long last, the ANOVA investigation was performed. The application of the pooled standard deviation yielded the following results:
One-way ANOVA: Daily hours usage versus Blurred eyesight & Dry eyes
Null hypothesisAll means are equal
Alternative hypothesis At least one mean is different
Significance levelα = 0.05
Equal variances were assumed for the analysis.
Factor Levels Values
Blurred eyesight & Dry eyes 4 1, 2, 3, 4
Analysis of Variance
Source DF Adj SS Adj MS F-Value P-Value
Blurred eyesight & Dry eyes325.508.500 1.23 0.390
S R-sq R-sq(adj) R-sq(pred)
2.62679 42.50%8.00% *
Dry eyes NMean StDev 95% CI
1 1 1.000* (-5.752, 7.752)
2 56.002.74 ( 2.98, 9.02)
3 25.502.12 ( 0.73, 10.27)
4 1 3.000* (-3.752, 9.752)
Pooled StDev = 2.62679
From the information gathered and the investigation done according to the diagrams, tables and factual examination above, it can be reasoned that there is an immediate relationship between the timeframe a man is presented to a working computer screen and the imperfections and disturbances they get in their eyes. The more drawn out the time one was presented to light from a computer screen, the more their eyes were inadequate. The investigation was, hence, fruitful in demonstrating the theory that participants with more hours of computer screen use every day creates visual perception issues. It is prescribed that further studies be did on courses in which light radiated by a computer screen can be diminished to eye-accommodating levels to check the expanding instances of eye imperfections. Numerous lengthy computer screen users experience different eye and vision related side effects and visual uneasiness.
Since huge numbers of the potential eye and vision issues identifying with computer screen use can be diminished or dispensed with by suitable change and position of the lengthy computer screen users, legitimate working environment outline and lighting control, great preventive vision care propensities and general proficient eye care. Through examination and clinical practice, optometry gives one of a kind and powerful means to address the vision issues and word related needs of lengthy computer screen users. Lengthy computer screen users and others worried with their eye wellbeing and vision ought to look for the guidance furthermore, help of specialists of optometry in their group with respect to the aversion, determination, treatment and/or administration of lengthy computer screen users related issues in the work environment. The American Optometric Association will keep on creating and circulate data to enhance open comprehension of the significance of good vision and ergonomics identified with the one of a kind requests of lengthy computer screen users utilize and will screen and offer its direction in the advancement of strategy and enactment identified with the regulation and utilization of computer screens.
Alexandre, M. M. and Milano A. (2006). Productivity and comfort effect of computer glasses for computer users Livermore National Laboratory. Livermore, CA 94550.
American Optometric Association, AOA, (2013). The effects of video display terminal use on eye health and vision. [Online]: http://www.aoa.org/optometrists/education-and-training/clinical-care/effects-of-video-display?sso
Bali, J. Navin N., and Thakur B. R. (2007). “Computer vision syndrome: A study of the knowledge, attitudes and practices in Indian ophthalmologists.” Indian Journal of Ophthalmology, vol. 55, pp. 289-293.
Bhandeni, D. J., Choundhary, S, and Doshi V. G. (2008). “A community based study of asthenopia in computer operators.” Indian Journal of Ophthalmology, Vol. 56, No.1, pp. 51-55.
Graney, M. C. (2011). Computer vision syndrome. A growing occupational health problem. [Online]: http://nurse-practitioners-and-physician-assistants.advanceweb.com/Features/Articles/Computers-Vision-Syndrome.aspx.
Price, K. M., and Richard M. J. (2009). The tearing patient: Diagnosis and management. Ed. Scott IU &Fekrat S. American Academy of Ophthalmology. [Online]: www.aao.org.
Schlossberg, E., Morrow, S., Llosa, A., Mamary, E., Dietrich, P. and Rempel, D. (2004). Upper extremity pain and computer use among engineering graduate students. American Journal of Industrial Medicine, 46(3), pp.297-303.
Shrestha, G. S., Mohamed, F. N. and Shah D. N. (2011). “Visual problems among video display terminals (VDT) users in Nepal.” Journal of Optometry, Vol. 4, No. 2, pp. 56-62.
Smita, A., Goel, D., and Sharma, A. (2013) “Evaluation of the factors which contribute to the ocular complaints in computer workers.” Journal of Clinical diagnosis, Vol. 7 No. 2, pp. 331-335.
Torrey, J. (2003). Understanding computer vision syndrome. Employ. Relat. Today, 30(1), pp.45-51.
Thomas, S. R. (2011). Statistical Analysis of Adverse Impact: A Practitioner`s Guide. AuthorHouse.
Watt, W. S. (2003). Computer vision syndrome and computer glasses. [Online]: http://lowvision.preventblindness.org/eye-condition/computer-vision-syndrome-and-computer-glasses.