The present research presents a novel method for investigating how characteristics of texts (words, sentences, and passages) and individuals (verbal and general cognitive skills) jointly influence eye-movement patterns over the time-course of reading, as well as comprehension accuracy. Fifty-one proficient readers read passages of varying complexity from the Gray Oral Reading Test, while their eye-movements were recorded. Participants also completed a large battery of tests assessing various components of reading comprehension ability (vocabulary size, decoding, phonological awareness, and experience with print), as well as general cognitive and executive skills. We used the Random Forests nonparametric regression technique to simultaneously estimate relative importance of all predictors. This method enabled us to trace the temporal engagement of individual predictors and entire predictor groups on eye-movements during reading, while avoiding the problems of model overfitting and collinearity, typical of parametric regression methods. Our findings both confirmed well-established results of prior research and pointed to a space of hypotheses that is as yet unexplored.