Transcript Computer Vision Syndrome (CVS)

Computer
Vision
Syndrome (CVS)
Submitted by John Wolf
Colorado State University
“The complex of eye and vision problems
related to near work experienced during
computer use.”
American Optometric Association
Did you know?
• CVS affects 90% of people
who spend three hours or
more a day at a computer.
• 143 million Americans
work on computer each
day.
• Decreased focusing
capability is corrected
with plus-powered overthe-counter eyeglasses.
• Reading glasses not best
solution for computer
use.
• Blink rate decreases to as
low as 6–8 blinks/minute
focusing on the computer
screen.
• The normal blink rate is
16–20 per minute.
• Even if don’t suffer from
symptoms may still
experience reduced
productivity and accuracy
at computer.
Symptoms
•
•
•
•
•
Headaches
Blurred vision
Neck pain
Fatigue
Eye strain
• Irritated eyes
• Double vision
• Difficulty refocusing
eyes
• Dry eyes
•Symptoms worsened by poor lighting and air
moving across eyes
•CVS only temporary and will decline after stopping
computer work
Why does this happen?
• Our eyes and brain react differently to characters on
screen than to printed characters
• Decreased blinking reflex while focusing on the
computer screen
• Uncorrected vision conditions
• Poor computer design
• Workplace ergonomics
• Highly demanding visual tasks
Prevention
• Over-the-counter
artificial-tear solutions
• Proper rest
• Consciously blink
• Often look out the
window to a distant
object
• Close eyes for 20
seconds, at least every
half hour
• "20-20-20 rule": every
20 minutes, focus the
eyes on an object 20
feet away for 20
seconds.
• Minimize glare
• Update display
• Adjust
brightness/contrast
Computer Ergonomics
• Ergonomics - Science of designing a job, equipment
and/or workplace to fit the worker.
• Tips to reduce risk of computer eye strain:
– Sit with head & neck in-line with torso, not bent down or
tilted back
– Avoid viewing screen with head turned or back twisted
– Keep elbows close to body
– Pick chair with lower back support, cushioned seat, and
contoured front edge
– Keep mouse close to key board
– Position monitor so top of screen is just above eye level
– Keep monitor close enough to read text without struggling
– Keep print documents at same height and distance as display
Productivity
• Direct correlation between proper vision
correction and time required to complete a
task on computer
Sources
• Wikipedia: http://en.wikipedia.org/wiki/Computer_vision_syndrome
•All About Vision: http://www.allaboutvision.com/cvs/ergonomics.htm
•DoctorErgo: http://www.doctorergo.com/faq.html
•Mdsupport: http://www.mdsupport.org/library/cvs.html