Basic guidelines on working on computers with the proper posture, protective wear, and the ergonomics

2. TOPIC: COMPUTER VISION SYNDROME
PRESENTER:USMAN ABDULWAHAB(NOI)
DATE: 14TH OCTOBER, 2015
VENUE: FEDERAL TEACHING HOSPITAL
GOMBE CONFERENCE HALL

3. OUTLINE
 INTRODUCTION
 DEFINITION
 BRIEF A & P OF LACRIMAL APPARATUS
 FACTS ON CVS
 AETIOLOGY OF CVS
 CLINICAL MANIFESTATION
 DIAGNOSIS
 TREATMENT OF CVS
 CVS AND WORKER PRODUCTIVITY
 RECOMMENDATIONS
 CONCLUSION

4. INTRODUCTION
 Computers have become part and parcel of our lives. Today,
in every corporate office , on the desk of every secretary
and executive , sits a computer that allows us to write,
design, compute , research and communicate faster than
we could before.
 Yet this conveniences has not come without a price to our
health and general comfort.
 Carpal Tunnel syndrome has become universally known
term, not so widely known is the computer vision
syndrome(CVS) which in fact is far more widespread.
 Computer vision syndrome describe a group of eye and
vision related problems that result from prolonged
computer use.

5. DEFINITION
 Computer vision syndrome (CVS) is described as a
group of eye and vision-related problems that results
from prolonged computer use (AOA,2009)

6. BRIEF ANATOMY AND PHYSIOLOGY
THE LACRIMAL APPARATUS
The lacrimal apparatus consist of :
Lacrimal gland
Accessory lacrimal glands
Lacrimal ducts
Puncta
Canaliculi
Lacrimal sac
Nasolacrimal duct

8. TEAR FILM
The tear film covers the normal ocular
surface. It comprise of the
following 3 layers
1. A superficial thin lipid layer (0.11
µm) – This layer is produced by
the meibomian glands, and its
principal function is to retard tear
evaporation and to assist in
uniform tear spreading
2. A middle thick aqueous layer (7
µm) – This layer is produced by
the main lacrimal glands as well as
by the accessory lacrimal glands of
Krause and Wolfring
3. An innermost hydrophilic mucin
layer (0.02-0.05 µm) – This layer is
produced by both the conjunctiva
goblet cells and the ocular surface
epithelium

9. FUNCTIONS OF TEAR FILM
Keeps the cornea and conjunctiva moist.
Provides nourishment to the corneal epithelium.
Washes away debris and noxious irritants.
Prevent infection due to presence of antibacterial
substance.
Facilitates movement of the lids over the globe.

10. AETIOLOGY/RISK FACTORS
The main cause of CVS is prolonged hours of computer use .
1. Environmental Factors
Temperature, chemicals, ventilation fans and ergonomics are
some of the environmental factors that can predispose one to
develop CVS.
2. Reduced Blink Rate
Most individuals normally blink between 10–16
times per minute. Studies have shown that the blink
rate at the computer is significantly less than
normal. A reduced blink rate contributes
to a poor tear film quality and temporarily stresses the
cornea.

11. 3. Increased Exposure
The reading of text on paper is normally performed
while looking downwards. This results in the
eyelid covering a substantial portion of the anterior
surface of the eye, thus minimizing the evaporation of
tears. On the contrary, computer users usually view
their reading material in a horizontal gaze. This results
in a wider palpebral fissure and an increased
surface area exposed to the effects of evaporation.

12. 4. Sex
The prevalence of dry eye is slightly greater in
females than males.
5. Age
Tear production normally decreases with age. Although
dry eye can occur at any age in both men
and women, post-menopausal women represent the
group of individuals most affected by dry eye.

13. 6. Systemic Diseases
Dry eye is associated with various systemic diseases.
A general review of the patient’s entire medical
history aids in establishing a complete diagnosis.
Autoimmune diseases such Sjogren syndrome and
rheumatoid arthritis have an association with dry eye.

14. 7. Systemic Medications
There are several systemic medications contributing
to dry eyes. The most prevalent medications
include diuretics, anti-histamines, psychotropics, and
anti-hypertensives.

15. 8. Ocular Conditions
Localized dysfunctions of the glands, which produce
the ocular tear film, can also contribute to dry
eye. The most common disorder, anterior blepharitis,
is an inflammation of the eyelids, affecting the
meibomian glands that secrete the lipid layer of
the ocular surface. The lack of an adequate lipid
layer contributes to rapid evaporation of the water
component of the tear film.

16. 9.Cosmetics
Poorly applied cosmetics can block the openings
of the oil-secreting meibomian glands. This in turn
contributes to a rapid evaporation of the water
component of the tear film.
10. Contact lens
Computer users suffer more ocular and vision
disturbance if they are also contact lens users.

17. FACTS ON CVS
 CVS holds the distinction of being called the number one
occupational hazard of the 21st century.( American
Optometrist Association (AOA),2014)
 About 88% of all computer users will develop CVS at some
time in their lives.( National Institute of Occupational
Safety and Health(NIOSH),2009).
 Operating a computer may lead to visual , muscular or
mental fatigue( Occupational Safety and Health
Administration(OSHA),2004).
 CVS affects productivity by 4-19%.(UAB,2010)
 Globally, Nigeria ranks number 8 with a population of
83,362,814 internet users ( NCC,2015).

18. CLINICAL MANIFESTATION
 Eye strain
Dry eyes
Red eye
Photosensitivity
Blurred vision
Headaches
Back and neck pain
Fatigue

20. DIAGNOSING CVS
Visual acuity test
History taking
General examination
Ocular examination
Refraction test
Schirmer’s test

23. TREATMENT
Treatment may consist of :
 Treating the underlying systemic or ocular condition
 Topical tears supplement
 Computer glasses
 Vision therapy

27. PREVENTION TIPS
 Move the location of your computer screen so that
your eyes are looking downward---about 10-20
degrees below eye level and 20-26 inches away from
the eyes.
 Place any reference material directly next to your
computer screen, so you don’t need to move your
head to look from the document to your computer
screen
 Adjust your chair height and position so that your
arms are parallel to the ground when typing, and
your feet are flat on the floor.

30.  Minimize glare on your computer screen by closing
windows or shades during the day and using anti-glare
screens can decrease the amount of light reflected on the
computer.
 Adjust the brightness and contrast on your computer
screen by making sure the brightness of the white is
neither too bright nor too dull , also ensure the contrast
between the screen background and the onscreen
characters is high.
 Adjust the text size and color for comfort, especially when
reading or composing long documents. Usually , black
print on a white background is the best combination.

31.  Avoid sitting in front of a fan or something like that
while working on a computer.
 Take frequent breaks, if possible rest your eyes by
stopping and looking into the distance for at least 10
minutes after an hour of continuous computer use.
 Use the “20-20-20” rule, look away from your computer
at least every 20 minutes and gaze at a distant object
that is at least 20 feet away for at least 20 seconds.

32. CVS AND WORKER PRODUCTIVITY
 If you use a computer at work, you probably already
know that a long day of staring at your screen can lead
to eye strain, tired eyes, headache, muscle aches and
other symptoms of CVS. But you may not know that
CVS also can lead to increase errors and reduce
productivity.
 And if you own a company, you might be interested to
know that studies suggest you can increase profits by
providing your employees vision care and computer
glasses to help boost productivity and decrease errors.

33. EMPIRICAL STUDY
A study conducted by Kent Daum(2009) at the
University of Alabama at Birmingham (UAB) School of
Optometry, examined the relationship between the
vision of computer workers and their productivity in the
workplace.
The study found:
 A direct correlation between proper vision correction
and productivity. This relationship particularly is
evident with complex and/or repetitive computer tasks
such as data entry.

34.  A direct correlation between proper vision correction
and the time required for a computer worker to
perform a task. Computer-related tasks took much
longer when the subjects wore glasses with less than
the optimum correction.
 Reduced productivity even among computer users who
were unaware they had vision problems. Computer
users with small refractive errors may not notice any
vision discomfort. But without proper vision
correction, their performance on a specific task can
suffer significantly — by as much as 20 percent

35.  The study strongly suggest that improving the visual
status of workers using computers results in greater
productivity in the workplace, as well as improved
visual comfort.

36. CHALLENGES
 Lack of awareness
 Lack of government policies
 High cost of computer glasses

37. RECOMMENDATIONS
Eye care professionals should endeavor to probe
patients that attend the clinic about the history of
computer use and spend time to discuss about CVS
during consultation.
Eye care professionals should alert builders and office
designers on the need to integrate internal decorations
that will mitigate the incidence of CVS which are
related to the workplace physical design and
lightening system.

38. Training institutions and health educators should
increase the level of awareness of CVS among
computer users thereby reducing the effects and
occurrence of CVS.
Training on computer –health related and safety
measures should be part of the curriculum of
computer training.
Companies and institutions with large number of
computer users should establish ergonomics
guidelines to protect computer users from ocular
hazards.

39. As practiced in the United kingdom, the Nigerian
government should also establish a legislation to
protect computer operators by setting out legal
requirements of employers for their computer
operators.
More studies need to be carried out on CVS to provide
an evidence-based information to the little literature
available on CVS in Nigeria.

40. CONCLUSION
 CVS can be an insidious occupational health problem.
However , with heightened client and employer
awareness , it can be easily prevented and treated.
 The health professionals can serve as diagnostic
clinicians, educators, advocates and workplace liaison
to help combat CVS.

41. REFERENCE
http://en.wikipedia.org/wiki/Computer_vision_syndr
ome
http://www.aoa.org
http://www.webmd.com/eye-health/computer-vision-
syndrome
http://www.emedicine.medscape.com
http://www.computervisionsyndrome.net
http://library.thinkquest.org
http://www.emedicinehealth.com/dry_eye_syndrome

42. THANK YOU FOR LISTENING