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Tactual reading is slow compared with sighted reading, and the rate-limiting constraints imposed on tactile readers are only vaguely understood. Like the eye movements of sighted reading, the text-scanning hand movements of tactual reading provide a means to investigate the operative system. We examined the reading hand movements of 10 blind readers using the Optacon, the electronic reading aid used most commonly by blind readers. Subjects read texts of graded difficulty, and their reading hand movements were recorded. Rate and scanning measures were used to characterize reading performance. The group mean reading rate was found to be 28.2 words/min. Reading rate measured in letter spaces per minute was independent of text difficulty.

Tactual reading usually requires the coordinated use of the forearm/hand motor and tactile sensory systems. Therefore, in a series of studies of tactual reading behavior, we chose to record the text-scanning patterns of adult blind readers in an attempt to gain further insight into the nature of this process. Reading behavior for four modes of tactual reading was recorded (embossed braille one-hand, embossed braille two-hands, Optacon/letterprint, and Optacon/Inkbraille) by detecting and recording the instantaneous position of light-emitting diodes unobtrusively attached to the finger(s) or the Optacon camera. In addition to the comparative evaluation of the four sets of reading patterns, the salient features of the Optacon/letterprint patterns were quantitatively analyzed in an attempt to characterize this particular mode of reading. The text-scanning patterns of Optacon readers have not been previously reported. In general the text-scanning behavior for all modes of tactual reading seems to be similar; the only remarkable difference appears to be in the reading rates. Regarding Optacon/letterprint performance, reading rate was found to be significantly and negatively correlated with line-changing time and the number of regressions. No significant correlation was evident between rate and regression magnitude.

A pilot study is explained comparing Inkbraille with embossed braille. Advantages of Inkbraille are noted and readability is tested.