The aim of this study was to assess contrast sensitivity for angular frequency
stimuli as well as for sine-wave gratings in adults under the effect of acute
ingestion of alcohol. We measured the contrast sensitivity function (CSF) for
gratings of 0.25, 1.25, 2.5, 4, 10, and 20 cycles per degree of visual angle (cpd) as
well as for angular frequency stimuli of 1, 2, 4, 24, 48, and 96 cycles/360°. Twenty
adults free of ocular diseases, with normal or corrected-to-normal visual acuity, and
no history of alcoholism were enrolled in two experimental groups: 1) no alcohol
intake (control group) and 2) alcohol ingestion (experimental group). The average
concentration of alcohol in the experimental group was set to about 0.08%. We used a
paradigm involving a forced-choice method. Maximum sensitivity to contrast for
sine-wave gratings in the two groups occurred at 4 cpd sine-wave gratings and at 24
and 48 cycles/360° for angular frequency stimuli. Significant changes in contrast
sensitivity were observed after alcohol intake compared with the control condition at
spatial frequency of 4 cpd and 1, 24, and 48 cycles/360° for angular frequency
stimuli. Alcohol intake seems to affect the processing of sine-wave gratings at
maximum sensitivity and at the low and high frequency ends for angular frequency
stimuli, both under photopic luminance conditions.