Page 78 - JSOM Summer 2018

FIGURE 1 All lights were Tomahawk tactical lights FIGURE 3 Tumbling E visual acuity.
(First-Light USA, https://www.firstlight-usa.com).

Farnsworth D-15 color vision (FD15) testing (Figure 4) and
pseudoisochromatic plate color vision (PiP) testing (Figure 5)
were performed using monochromatic red and green lights
as well as polychromatic white, duochromatic red/green and
multihue red/green/yellow lights. PiP testing is sensitive for
detecting color blindness; FD15 testing is sensitive to color
blindness and specific to the varying type of color blindness.
Participants were seated for FD15 and PiP testing and the tiles
or PiPs were on a table in front of them. The FD15 test used a
control tile and the participants arranged the remaining tiles in
a color gradient. The absolute error of each tile was recorded
upon completion. PiPs were illuminated and the total number
and duochromatic green/red are all commercially available wrong was recorded.
from First-Light USA; the multihue green/red/yellow light was
a prototype requested by the investigators and made by First- FIGURE 4 Farnsworth D-15 color vision testing.
Light USA to investigate whether there might be an advantage
to the additional hue.

Pelli-Robson near contrast sensitivity (PR) testing (Figure 2) and
tumbling E visual acuity cube (Figure 3) were performed with
monochromatic green, red, and blue lights, ands polychromatic
white, duochromatic green/red, duochromatic blue/red, and
multihue green/red/yellow lights. Participants were standing for
visual acuity and contrast sensitivity testing. The PR chart was
placed 40 inches from the participants and it was scored ac-
cording to the log contrast score of the chart as dictated by the
last full triplet of letters read. The tumbling E vision cube was
placed 10 feet from the participant. The volunteers were then
asked to identify in which direction the E was pointing (i.e., up,
down, left, or right) and visual acuity was recorded based on the FIGURE 5
Pseudoisochromatic plate
smallest E the participant was able to identify. color vision testing.

Statistical Analysis
FIGURE 2 Monochromatic blue and polychromatic blue/red were not in-
Pelli-Robson near cluded in color-vision testing. The paired Student t test was
contrast sensitivity used to compare data from each test with that obtained when
testing.
using the white light control and to compare the mean stan-
dard deviation between the performance of the individual par-
ticipant under different light hues.

P ≤ .05 for the comparison of a light variable and white light
was considered statistically significant (i.e., the participant’s
performance on the test using that light hue was statistically
worse than their performance when white light was used).

76 | JSOM Volume 18, Edition 2/Summer 2018