GSR latency, mean amplitude and quiescent or post reading time during and after reading paragraphs of 20/50 acuity level or 1.5 mm letters at four low illumination levels were investigated. The Beckman Dynograph with miniature skin electrodes was used to record the GSR of twelve male college students. Results showed that this range of illumination has no effect on latency or post reading response time but that the curve for amplitude vs. illumination is linear.