7. Glare reduction testing on humans and correlation to
empirical measurements
This section deals with glare reduction ratings on
printed-paper by a panel of people and correlation of
these ratings to light meter measurements of glare
reduction and, as a reference, the theoretical percent
glare reduction on glass. The easily measured variables
of fluorescent lamp height and lamp to desk edge
distance were used to vary the viewing angle and,
subsequently, the percent glare reduction. If the results
for glare reduction ratings from human testing give the
same optimizational trend as in Fig. 8, the use of the
theory for workstation lighting design is justified.
Rather than a glass surface, this study includes testing
on two different papers with and without bright, diffuse
ambient lighting illuminance superimposed on the
illuminance of the fluorescent task light.
The selection of 30 experimental subjects (17 females
and 13 males) provided for near equal weighting of age
and gender within the four decades of age groups (20,
30, 40, 50 years) normally encountered in the workplace.
Test subjects with eye correction totaled 17 with
eyeglasses and 7 with contact lenses.
The Fig. 8 plot of theoretical percent glare reduction
optimization for different lamp heights and distances
may be regarded as a contour plot (response surface) of
the change of the independent variable (% glare