In this study, the stereo vision without optical aid was explored concerning the following problems; the way we made stereo pictures, the way we saw stereo vision simply, and we observed the change of stereo vision. From the first of these above problems, we used central projection, right projection, and oblique projection. As for the second, stereo pictures were added like next: assumptive construction (e.g. to add simple solid like a cube.) : technical hand (e.g. to color the corresponding sides of two stereo pictures.) perspective comparison (e.g. to use circles of different size which are variable according to the distance.) As for the last we observed the variation of apparent size or shape which were affected by direction or distance.
