The objective is to determine if a person blinks less, and therefore vision worsens after reading and working on the computer.

Informed consent was obtained from 15 subjects, men and women ranging in age from 10 to 103. Structured questionnaires were administered to 100 computer users aged between 18 and 40 years. The study findings revealed that 40 respondents (40%) were aware of CVS and 27 (27%) of them had knowledge of the disorder. 74 (74%) of the respondents experienced at least one symptom of CVS. Headache and eyestrain were the most common symptom of CVS among the population. The study also revealed that the internet (accounting for 50%) was the major source of information about CVS awareness. The study concluded that 27% knowledge level is too low and much emphasis is needed to educate the people at risk of CVS







Background to the study

When the first IBM personal computer was manufactured in 1981, the company did not envisage the possible potential health hazards the users may consequently experience (Mvungi, Mcharo, Mmbuji, Mgonja & Kitua 2009, p.69). Today, a condition known as Computer Vision Syndrome (CVS) is common to millions of computer users around the world. A syndrome is defined as a group of signs and/ or symptoms which occur together to produce a pattern typical of a particular disease (Pocket Medical Dictionary 1987, p.256). CVS is characterised by a complex group of eye and vision-related problems that result from prolonged computer use (Bali, Navin & Thakur 2007, p.290).

Nearly 60 million people suffer from CVS globally and a million new cases occur each year (Sen & Richardson 2007, p.45). Symptoms of CVS occur in approximately 75-90% of computer users (Anshel 2007, p.37). Studies conducted in Nigeria have shown that CVS may result in lowered productivity, increased error rate, reduced job satisfaction, impaired visual abilities and blurred distant vision (Chiemeke, Akhahowa & Ajayi 2007, p.1).

Mvungi et al (2009, p.73) also reported that most problems associated with the use of the computer can be largely attributed to improper use of computers and most importantly, insufficient knowledge about safe computer usage techniques and practices. Most CVS-related problems can be avoided by appropriate preventive measures, but the majority of computer users are not aware of CVS-related symptoms while some choose to ignore them (Divjak & Bischof 2009, p.350).

The research problem is derived from clinical practice. The case history records from a private eye clinic in Abuja, Nigeria show that one of the most common complaints by patients is eyestrain during computer use. The records also show that a large proportion (about 90%) of people with these complaints work with computer for prolonged hours (at least 4 hours daily) and were diagnosed to suffer from Computer Vision Syndrome. The research questions therefore include:

(i) How much do the computer users know about this disorder?

(ii) What is the extent of CVS among computer users in the selected workplace?

(iii) Will a good knowledge of CVS and its preventive measures reduce the number  of patients seeking relief from computer-related stress?

Extensive literature search did not reveal any study that assessed the knowledge of computer users about CVS in Abuja, Nigeria, hence the rationale for this study. To successfully address this public health issue, there is a need to assess the knowledge of the people at risk, so that adequate measures can be developed.

There is sufficient evidence in the literature that a large number of computer users  suffer from CVS (Ihemedu & Omolase 2010, p.49; Sen & Richardson 2007; Torrey 2003). In the USA more than 143 million Americans work on a computer each day with an estimated 90% suffering from computer eyestrain. Additionally, almost 90% of children in the USA work on a computer at home or in school every day (LFV [n.d.]; VCA 2007). Computer use in Nigeria has attained a significant patronage especially  with the upsurge of information and communication technology systems as most organisations barely manage their businesses without it. However, poor publicity and

utilisation of preventive measures have hampered the effectiveness of computers due to the overwhelming symptoms experienced by some users (Ihemedu & Omolase 2010, p.51). Awareness of visual problems from computer use has also been minimally stressed in most industrially developing countries like Nigeria (Chiemeke et al 2007).

CVS is caused by the eye and brain reacting differently to characters on the screen than they do printed characters. Characters on a computer screen lack the contrast or well defined edges that printed characters have. Because the colour intensity of digital characters diminishes around the edges, it is difficult for eyes to remain focused. Having to continuously refocusing on digital text fatigues the eyes and can lead to burning or tired eyes. CVS is marked by symptoms such as eyestrain, burning sensation, blurred vision, gritty sensation, headache and neck pain. Some computer users may experience continued reduced visual abilities such as blurred distant vision even after work (Chiemeke et al 2007). These symptoms may be aggravated by poor lighting, glare, improper work station set up and uncorrected refractive errors (Ihemedu & Omolase 2010, p.49; Torrey 2003). Though symptoms such as burning sensation and gritty sensation have been reported by people exposed to dusty environments, it is however not clear whether these symptoms occur to a greater extent in computer users than workers in other highly visually demanding occupations (Chiemeke et al 2007).

A study conducted by Chiemeke et al (2007) in Benin, Nigeria tested the respondents’ knowledge on computer ergonomics and preventive measures of CVS. Results from the study showed that only a small percentage (32%) of the respondents was aware of preventive measures for visual symptoms, while a minority (1%) had former ergonomics guidelines/ policies at their workplace. Similar studies in south-west Nigeria (Ihemedu & Omolase 2010) show that a large number of respondents were aware of various types of computer shields but only a few utilised the shields. Studies from other parts of Africa show that most problems associated with computer use are caused by insufficient knowledge about safe computer usage (Mvungi et al 2009, p.73).

CVS remains an underestimated and poorly understood issue at the workplace (Izquierdo, Garcia, Buxo & Izquierdo 2004, p.103). About 70% of computer workers worldwide report having vision problems and there is an alarming increases in the number of people affected (Blehm, Vishnu, Khattak, Mitra & Yee 2005). Not much is known about CVS among children in Africa who are also increasingly becoming regular computer users. Some researchers (Divjak & Bischof 2009, p.350; Mvungi et al 2009, p.69) explain that CVS can be avoided by suitable preventive actions but majority of the sufferers are ignorant of this. In this light, some eye care professionals have referred to CVS as the number one occupational epidemic of the 21st century (Graney [n.d.]; Torrey 2003).


Mounting evidence shows that CVS can significantly harm workplace productivity, as it places an unusual strain on the human physical well-being thereby reducing the quality of life (Torrey 2003). Studies by Izquierdo et al (2004), Chiemeke et al (2007), Divjak & Bischof (2009) have shown a direct correlation between proper vision correction and the time required for a computer worker to complete a task; and that productivity is reduced even more among computer users who were unaware that they had vision problems. CVS is therefore a significant public health problem as it affects computer users from all walks of life (Torrey 2003).

Current management of CVS in Nigeria makes little emphasis on educating computer users. It is therefore imperative to assess the knowledge about CVS and level of awareness of its preventive measures among computer users in order to develop strategic interventions to reduce the effects of CVS among computer users and identify areas in which educators will concentrate their efforts.


The main purpose of the study is to assess effects of reading and working on the computer on vision specifically the study aims to:

(i) To explore the level of knowledge and awareness about CVS among computer users.

(ii) To determine the extent of CVS by assessing the visual symptoms among the study population.


The study will contribute as evidence-based information to the little literature available on CVS in Nigeria. Information about CVS knowledge will help employers and other stakeholders to develop strategies that will be used to reduce the effects of CVS in the selected population. The strategies, if eventually applied would help reduce the loss of productivity in the workplace and the associated visual discomfort.

Training institutions and health educators will find the information useful for developing and revising training curricula that will enhance knowledge and level of awareness of CVS among computer users. This will contribute to the reduction in the occurrence and effects of CVS in Nigeria.


  1. what is the level of knowledge and awareness about CVS among computer users?
  2. what is the extent of CVS by assessing the visual symptoms among the study population?

Scope of the study

This study on the effects of reading and working on the computer on vision will focus on the computer vision syndrome in workplace in Abuja. In this study the workplace refers to the Securities and Exchange Commission (SEC) headquarters in Abuja, Nigeria


Depth or accuracy of the knowledge of CVS may not be ascertained due to the instrument used (structured questionnaire). Therefore, respondents who indicate familiarity with CVS may only have a shallow knowledge of the disorder.

Generalisability of the findings may be limited, since only one institution will be included in the study.



Conceptual definition: The fact or condition of knowing something with familiarity gained through experience or association (Merriam-Webster 2011).

Operational definition: Knowledge in the study will be defined as having some understanding of CVS.


Conceptual definition: Knowing that something exists (Oxford advanced learner’s dictionary 2006, p.88).

Operational definition: Awareness in this study will be defined as having heard of CVS.

Computer Vision Syndrome

Conceptual definition: A complex group of eye and vision-related problems that result from prolonged computer use (Bali et al 2007, p.290).

Operational definition: Eyestrain, blurred vision and headache that occur as a result of computer use (Chiemeke et al 2007).


Conceptual definition: Office, factory or place where people work (Oxford advanced learner’s dictionary 2006, p.1698).



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