In the present study, we used a scanpath approach to investigate reading processes and factors that can shape them in monolingual Russian-speaking adults, 8-year-old children, and bilingual Russian-speaking readers. We found that monolingual adults' eye movement patterns exhibited a fluent scanpath reading process, representing effortless processing of the written material: They read straight from left to right at a fast pace, skipped words, and regressed rarely. Both high-proficiency heritage-language speakers' and second graders' eye movement patterns exhibited an intermediate scanpath reading process, characterized by a slower pace, longer fixations, an absence of word skipping, and short regressive saccades. Second-language learners and low-proficiency heritage-language speakers exhibited a beginner reading process that involved the slowest pace, even longer fixations, no word skipping, and frequent rereading of the whole sentence and of particular words. We suggest that unlike intermediate readers who use the respective process to resolve local processing difficulties (e.g., word recognition failure), beginner readers, in addition, experience global-level challenges in semantic and morphosyntactic information integration. Proficiency in Russian for heritage-language speakers and comprehension scores for second-language learners were the only individual difference factors predictive of the scanpath reading process adopted by bilingual speakers. Overall, the scanpath analysis revealed qualitative differences in scanpath reading processes among various groups of readers and thus adds a qualitative dimension to the conventional quantitative evaluation of word-level eye-tracking measures.