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Computer Vision Syndrome: Remediation

Continued from: Computer Vision Syndrome

The most typical symptom of Computer Vision Syndrome (or CVS) is 'Dry eye'. Most common factors that can cause 'Dry eye' are:
  • Decreased blink rate
  • Lid conditions
  • High gaze angle
  • Low humidity
  • Contaminants in environment
  • Air conditioner vents
How to take care of 'Dry eyes'?
  • Blink more (15-20 times/min)
  • Treat lid conditions – Meibomitis/ Blepharitis
  • Artificial tears
  • Air conditioner vent away from face
  • Low gaze angle
  • Ergonomics

While most other factors are manageable and controllable, 'Ergonomics' is usually ignored. Apparently, it is the biggest contributor causing CVS.

Ergonomics is 'the study of designing equipment and devices that fit the human body, its movements, and its cognitive abilities. Proper ergonomic design is necessary to prevent repetitive strain injuries, which can develop over time and can lead to long-term disability.'

Ergonomics is assessed over four these categories:
  • Lighting, Glare and Reflection
  • Monitor, Keyboard and Mouse
  • Posture
  • Visual Hygiene
Lighting
  • Position of lighting
  • Type of lighting: Indirect over Direct
                           
Direct Lighting
Indirect Lighting
      
Advantages of Indirect Lighting:
  • Distributes light more evenly than direct lighting systems
  • Eliminates glare and shadows
Disadvantages:
  • Higher installation cost
  • Fixture reflectors and room surfaces must be cleaned regularly to ensure maximum performance
Management of Glare and Reflections
  • Add dimmer switches to overhead lights/coverings on fluorescent lights.
  • Relocate lamps causing reflections on screen.
  • Non-reflective paint /coverings on walls facing computer.
  • Eliminate exterior light –drapes, blinds, shades with a screen/partition behind computer to reduce outside light /overhead glare.
Black on white (High contrast between screen background and characters)
  • Equipment with brightness controls
  • Brightness match
  • Work in down gaze , angling of monitor
  • Glare guard -an optically coated glass anti-glare filter on CRT monitor
Monitor
  • Working distance of 50-60 cm
  • Centre of screen to be 4 –9 inches below eye level
  • The 3x test - Character size should be three times the size for threshold recognition



Chair
  • Height adjustment
  • Knee angle more more or equal to 90 Degree
  • Foot rest
  • Back straight
  • Lower back support
  • Arms rest
  • Direct in front
Keyboard / Mouse
  • Lower than elbow
  • Nearer to the body
  • To be flat
                 
Keyboard Posture
                
Mouse Posture

Wrist
  • Straight while typing
  • Wrist pad
  • Carpal Tunnel Syndrome

Ideal Workstation
  • Distance between eyes and monitor – 20”- 26”
  • Monitor angling should be 10 °-20° backwards
  • Arm angle –100 °- 90 °
  • Straight back – 90 °
  • Knee angle - 90 °
Laptop - Ergonomics
  • External keyboard placed on an adjustable keyboard platform at elbow height
  • Attach an external mouse instead of using the small constricted touchpad or trackball.
  • If sitting on a couch, use a pillow to support arms.
  • Place the Laptop on a stand, book or other surface that raises it to a height that the screen is viewed without having to bend or rotate the neck.
  • Raise the screen To Proper viewing level
  • Separate keyboard and Mouse
                  
Ideal Workstation Posture
Ideal Laptop Posture
Visual Hygiene
  • Good habits for good vision
  • Visual training -exercise
  • 10 minutes break every hour
  • Blink rate: 15 -20 times/ min
  • Organized work station



Comments

  1. For me definitely useful ! :)

    ReplyDelete
  2. good article, thank you very much for the share.

    ReplyDelete

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