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Main content start

Eyecare course

 

Home | Introduction | Eye and Vision | Common eye problems in students | Common eye problems related to the use of digital screen devices | Management and prevention of Computer Vision Syndrome

 

#

Common eye problems related to the use of digital screen devices

 

 4.1 Objective: To know about the common eye problems caused by the use of digital screen devices and the definition of Computer Vision Syndrome (CVS)
 

By completing this chapter, you will learn the following list of topics:

  • Bad habits may lead to eye problems related to the use of digital screen devices
  • Computer Vision Syndrome (CVS)
  • Differences between reading digital screen and paper
  • Causes of dry eye
  • Other symptoms of CVS
 #

4.2 Common eye problems related to the use of digital screen devices
The use of digital screen devices to view small type for prolonged periods, frequently at close working distances, has become commonplace in modern society. #
 # 

Many individuals use multiple devices such as a desktop and laptop computers as well as one or more hand-held devices. These present a variety of visual demands that are significantly different from those of printed materials in terms of working distances, viewing angles and text sizes.

  

  

 4.3 Bad habits may lead to eye problems related to the use of digital screen devices 
 

There are several bad habits that may lead to the development of eye problems related to the use of digital screen devices.

5 signs for at risk behaviours

 
  

 

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Using digital screen devices for prolonged periods (>1 hour) without restRubbing eyes while using digital screen devices Frowning and squinting while using digital screen devices

Holding digital screen devices too close
( < 16 inches or < 40 cm )

Lack of blinking

  

 4.4 What eye problems can occur after prolonged use of digital screen devices?
Staring at your computer screen, smartphone, or other digital screen devices for long periods may cause a number of eye problems. Computer Vision Syndrome (CVS) is a term to describe these eye problems, and may affect up to 90% of computer users.
 #
 

The symptoms may include asthenopia (eyestrain), headaches, dry eye, diplopia (double vision) and blurred vision after prolonged use (>1 hour) of computer or other digital screen devices.

  

4.5 What are the differences between reading digital screen and paper?
Digital Screen DevicePaper
#

Digital screen is self-illuminated.

The brightness of digital screen

is associated with visual fatigue.

Whereas paper relies on the reflection of light.

  

4.5 What are the differences between reading digital screen and paper?

 

Digital Screen DevicePaper
#

Objects displayed on digital screen consist of a series of pixel-based dots with decreasing brightness on their outer edges, thus making it hard for eyes to focus

Objects on paper are printed with solid ink images

 

Digital Screen Device Paper 
 #

Digital screen has different resolutions that affect visual fatigue and readability, whereas paper does not have this resolution issue.

 

4.6 What are the causes of dry eye?#

 

Dry eye is a major symptom of CVS. It can cause both eye discomfort and blurred vision. There are three major mechanisms that may underlie the development of dry eye after prolonged use of digital screen devices.

 

 #  Increased corneal exposure from viewing angle
 Reduced blinking frequency Reduced blinking amplitudeComputers are usually used with the eyes in the primary position, whereas hardcopy text is more commonly read with the eyes depressed. The higher viewing angle increases corneal exposure and tear evaporation. 
# 
People normally blink about 15 to 18 times a minute. We blink about half that often while concentrating on using computers or other digital screen devices

Incomplete blinking is commonly seen in people using digital screen devices, resulting in inadequate spreading of tears across and removal of irritants from the surface of the cornea. 

# 

# 
   #
 # #
Excess static electricity Air-borne contaminants
 # #
 Low ambient humidityHigh forced-air heating

 

 

 

All of the above mechanisms contribute to the development of dry eye after prolonged use of digital screen devices. In addition, there are several environmental factors that can further increase corneal drying, such as low ambient humidity, high forced-air heating or air conditioning settings, and excess static electricity or air-borne contaminants. #
  

 

4.7 What are the causes of other symptoms of CVS?
Besides dry eye, sustained accommodation and convergence for a prolonged period of time while viewing the screen of digital screen devices may also contribute to the symptoms of CVS, particularly eyestrain, double vision, and headaches. These CVS symptoms can be further aggravated by improper lighting conditions (e.g., glare or bright overhead lighting) and uncorrected refractive errors (e.g., myopia, astigmatism).#
 # ### 
Bright lightingGlare lightingMyopiaAstigmatism

 

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 4.8 Summary

Congratulation! You have completed Chapter 4. You should now be able to understand the following topics.

 
  • Bad habits may lead to eye problems related to the use of digital screen devices
  • Computer Vision Syndrome (CVS)
  • Differences between reading digital screen and paper
  • Causes of dry eye
  • Other symptoms of CVS