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 over-the-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