Eye movements in reading and other information processing tasks have been studied extensively over the past 20 years. This review focuses on reading as a cognitive processing task, discussing key aspects such as eye movement characteristics, perceptual span, information integration across saccades, eye movement control, and individual differences. The review highlights that eye movement data reflect moment-to-moment cognitive processes in various tasks. The third era of eye movement research, beginning in the mid-1970s, has seen significant technological advancements, enabling more accurate and efficient data collection and analysis. Eye movements, such as saccades, are rapid eye movements that occur between fixations, during which visual input is reduced due to saccadic suppression. Fixations last about 200–300 ms, and saccades can reach velocities of up to 500° per second. The duration and length of saccades vary depending on the task. Saccade latency, the time required to initiate a saccade, is typically around 150–175 ms and is influenced by cognitive processes. The visual field is divided into foveal, parafoveal, and peripheral regions, with the fovea providing the highest visual acuity. Eye movements are closely related to attention, with attention preceding saccades and being closely coupled with them. Developmental changes in eye movements are also discussed, noting differences between children and adults. Eye movements are measured using various techniques, including surface electrodes, infrared corneal reflections, and video-based pupil monitoring. In reading, eye movements differ between silent and aloud reading, with silent reading involving shorter fixations and larger saccades. The perceptual span in reading is relatively small, extending from the beginning of the fixated word to a few letters to the left or right of fixation, depending on the writing system. The size of the perceptual span is influenced by the writing system and reading skill. The results of studies using eye movement data suggest that cognitive processes can be inferred from eye movement patterns, although there are ongoing debates about the best measures of processing time. Overall, eye movement research has provided valuable insights into the cognitive processes involved in reading and other information processing tasks.Eye movements in reading and other information processing tasks have been studied extensively over the past 20 years. This review focuses on reading as a cognitive processing task, discussing key aspects such as eye movement characteristics, perceptual span, information integration across saccades, eye movement control, and individual differences. The review highlights that eye movement data reflect moment-to-moment cognitive processes in various tasks. The third era of eye movement research, beginning in the mid-1970s, has seen significant technological advancements, enabling more accurate and efficient data collection and analysis. Eye movements, such as saccades, are rapid eye movements that occur between fixations, during which visual input is reduced due to saccadic suppression. Fixations last about 200–300 ms, and saccades can reach velocities of up to 500° per second. The duration and length of saccades vary depending on the task. Saccade latency, the time required to initiate a saccade, is typically around 150–175 ms and is influenced by cognitive processes. The visual field is divided into foveal, parafoveal, and peripheral regions, with the fovea providing the highest visual acuity. Eye movements are closely related to attention, with attention preceding saccades and being closely coupled with them. Developmental changes in eye movements are also discussed, noting differences between children and adults. Eye movements are measured using various techniques, including surface electrodes, infrared corneal reflections, and video-based pupil monitoring. In reading, eye movements differ between silent and aloud reading, with silent reading involving shorter fixations and larger saccades. The perceptual span in reading is relatively small, extending from the beginning of the fixated word to a few letters to the left or right of fixation, depending on the writing system. The size of the perceptual span is influenced by the writing system and reading skill. The results of studies using eye movement data suggest that cognitive processes can be inferred from eye movement patterns, although there are ongoing debates about the best measures of processing time. Overall, eye movement research has provided valuable insights into the cognitive processes involved in reading and other information processing tasks.