Full spectrum light full spectrum light bulbs full spectrum lighting full spectrum lights spectrum lighting natural spectrum light bulbs fluorescent lighting balanced spectrum lighting spectrum light bulb natural light full spectrum light for sad full spectrum fluorescent light natural light bulbs natural lamp light full color spectrum lighting full spectrum fluorescent lighting phillips natural light studio lighting natural light tubular skylight true light showroom lighting full spectrum fluorescent light bulbs natural spectrum light natural light source natural light light bulbs crslight.com


Effects of using an optical glass glare filter on computer worker's visual health and performance:
Results of an ergonomic field study

-excerpts from Cornell Human Factors Laboratory Technical Report/RP196


The results from three surveys of almost 200 computer workers in 8 buildings will be described. An initial survey asked about baseline office lighting and screen glare problems. A second survey was conducted about one-month after two thirds of the workers received a glass, glare and anti-static screen filter, the rest served as a control group. The final survey was conducted about one month after the control group workers received their glare filters. Measures of illuminance and screen luminance contrast were taken at 117 work stations., Results showed that workers rated very positively to the glare filters. Following glare filter installation rating s of various screen image attributes and of visual health problems were substantially improved. The glare filters effectively minimized electrostatic shocks to workers Most workers liked their glare filters and reported improved productivity.


Results from this study allow that worker reactions to the glare filters were very positive. Workers reported that the glare filters improved the quality of several screen attributes, such as contrast. Also, the glare filters reduced complaints of screen glare, and improved workers' ratings of visual health and productivity. The glare filters tested in this study include a conductive coating to eliminate electrostatic fields in front of the computer screen. After using the glare filter complaints of electrostatic shock and screen dustiness were reduced. Use of the glare filter did not affect workers' ratings of the quality of the office lighting.

In summary, the research found:

  • 80% of users reported that the filters made it easier to read their screens and more than 50% said that the filters helped their productivity.
  • 89% said that the filters improved the quality of the screen image by enhancing sharpness, contrast, color and brightness.
  • 73% said text was clearer with the glare filter; 34% said there was less screen flicker with the filter.
  • use of the glare filter reduced the prevalence of the following symptoms:
  • 50% decrease in lethargy/tiredness; trouble focusing eyes; dry eyes
  • 40% decrease in itching/watering eyes; headaches

Overall, worker reactions to use of the glare filter were extremely positive, and the vast majority of workers said that they liked using this. In conclusion, results from this research show that the use of this type of optical glass glare filter can help to improve the visual experience for many computer workers.

Effects of glare filters on reports of health symptoms. (Click here for ordering information)

Tired eyes
Trouble focusing eyes
Itching/watering eyes
Dry eyes
- without Glare Guards
- with Glare Guards
% workers reporting 'daily' or 'weekly' symptoms


These results confirm that the glare filters were successful in reducing the amount of glare on the computer screen. Workers generally were enthusiastic about their glare filters. One worker wrote:

    "The difference is tremendous! Sometimes I lift the glare screen a little as a reminder of what I'm missing out on."
    Others said:
    "I'm so glad to have it! Has made a big difference in amount of eyestrain! Thank you!"
    "Thanks for the opportunity to participate, never realized how much screen (filter) could help - no more headaches!"
    "Great for cutting down eyestrain;, thanks for including me in your survey."

    (Click here for ordering information)


For other pertinent topics, see left navigation bar and view topics below:


The Joy of Seeing Colors!
Color for Professionals
Does Light Go Beyond Vision?
Our Bulbs and Glare
Our Bulbs and UV Radiation
Children and Light
Seniors and Light
Light and Animals
The Secret of Color Correct Lights
Seeing Better with Optically Treated Glare Filters



© 1999-2003 CRS Light