Pattern Glare Test
Participants viewed one of the grating patterns from the PGT (Wilkins et
al., 1984). Because the online format precluded monitor calibration and
validations of cycles per degree were not possible. Because it is high
contrast and robust to various screen settings, we presented a
medium spatial frequency image (horizontal square-wave grating at a
Michelson contrast of ~0.7) for 5 seconds, based on
Pattern 2 of Wilkins and Evans (2001) PGT ; see Figure 1. Participants
were asked to fixate on the central fixation point embedded in the
image. They were asked to endorse percepts via mouse click from the
following options: pain/discomfort, shadowy shapes amongst the lines,
shimmering of the lines, flickering, colors, blur, bending of the lines,
nausea/dizziness, unease, other, and none of the following. Participants
could select as many options as they wished.