Some stereoblind observers do not perceive depth of 3D stimuli that depends on binocular disparity. These individuals, who have no disabilities, comprise over 5% of the general population. In addition, 17-30% of nonstereoblind young and young-middle people do not use disparity information in certain 3D environments, a phenomenon known as pseudo-stereoblindness. This study aimed to investigate the relationship between aging and the proportion of pseudo-stereoblindness in the general population. In an experiment, 134 nonstereoblind participants, ranging in age from 17 to 83 years, judged subjective depth of 3D stimuli containing binocular disparity and pictorial depth cues. Results showed that the proportion of pseudo-stereoblindness among young (17-24 years old) and young-middle aged observers (25-39 years old) was 29%, in both cases. However, the proportion of pseudo-stereoblind observers increased in older populations: 65% and 82% in the middle (40-54 years old) and senior (55-83 years old) age groups, respectively. These results suggest that a number of people, especially in elderly populations, have trouble perceiving depth from binocular disparity in 3D graphic contents despite their essential ability to use disparity information.