So, a friend of mine once submitted a design for an eye tracking device which was cheap to build to a science fair, and it placed. It went something like this, you have a box with view-holes in it. Inside the box is a slanted two-way mirror. Above the box, and pointing down into it is a video projection, which casts it's image onto the mirror which reflects and is viewable by the user of the device. Opposite the view-hole side, is a camera, pointing in and through the transparent side of the mirror, which records the motion of the users eyes.

If we assume that a person under the influence of pattern inducing substances is able to trace the lines of slow, or even fast moving patterns with their eyes, I think that to some degree the patterns seen could be represented with a rotoscoping technique, the eye patterns being redrawn as lines over the video or images displayed to the user during the experiment.

Just an idea though.