立体視教材試作のための基礎研究 : 静的立体視不良者における視能特性の評価

The characteristics of the visual function of students with poor static stereopsis need to be clarified prior to manufacturing an experimental learning aid for teaching stereopsis. Therefore, we evaluated individual quantitative visual functions, including parvocellular, magnocellular, ventral and dorsal pathway functions. Our subjects were 118 students who had received training to become orthoptists. Based on a survey of their static stereopsis, these subjects were categorized into four groups: good stereopsis, unstable stereopsis, poor stereopsis and no stereopsis. We evaluated the parvocellular, magnocellular, ventral and dorsal pathway functions in the latter three groups. To evaluate the parvocellular and ventral pathways, static stereopsis was examined using the Titmus stereo test. To evaluate the magnocellular and dorsal pathways, contrast sensitivity was examined using frequency-doubling technology, and motion stereopsis was examined using the MV-200. Three of 118 (2.5%) students were in the unstable stereopsis group, three (2.5%) were in the poor stereopsis group and two (1.7%) were in the no stereopsis group. Thus, we concluded that trial production of a learning aid for stereopsis training using a dynamic approach would be useful for students with abnormal magnocellular and dorsal function

Interstellar Extinction Law toward the Galactic Center II: V, J, H, and Ks Bands

We have determined the ratios of total to selective extinction directly from observations in the optical V band and near-infrared J band toward the Galactic center. The OGLE (Optical Gravitational Lensing Experiment) Galactic bulge fields have been observed with the SIRIUS camera on the IRSF telescope, and we obtain A(V)/E(V-J)=1.251+-0.014 and A(J)/E(V-J)=0.225+-0.007. From these ratios, we have derived A(J)/A(V) = 0.188+-0.005; if we combine A(J)/A(V) with the near-infrared extinction ratios obtained by Nishiyama et al. for more reddened fields near the Galactic center, we get A(V) : A(J) : A(H) : A(Ks) = 1 : 0.188 : 0.108 : 0.062, which implies steeply declining extinction toward the longer wavelengths. In particular, it is striking that the Ks band extinction is \approx 1/16 of the visual extinction A(V) much smaller than one tenth of A(V) so far employed.Comment: 8 pages, 7 figures, Accepted for publication in Ap