In the majority of cases, the primary means of information input to operators in nuclear power plant (NPP) control rooms is through the visual channel. In this study, eye movement patterns of NPP operators are analyzed with eye-tracking data obtained from simulator-based experimental studies. Two eye-tracking measures of attentional-resource effectiveness in monitoring and detection tasks in NPPs that have been developed by the authors are introduced, and several applications with the two eye-tracking measures are discussed for use of the measures. The underlying principle of the measures is that information sources should be selectively attended according to their importance. One of the two measures is the fixation-to-importance ratio (FIR), which represents attentional resource (eye fixations) spent on an information source compared to the importance of the information source. The other measure is selective attention effectiveness (SAE), which incorporates the FIRs of all information sources. The FIR represents the effectiveness of an information source, whereas the SAE represents the overall effectiveness of all information sources. Frequency and duration of eye fixations of an operator on information sources are used as the attentional resource. Finally, insights on future applications of eye-tracking data coupled with other psychophysiological measurement techniques to nuclear human factors are addressed on the basis of advances of fourth industrial revolution technologies.