This study investigates the region from which skilled readers acquire visual information during a fixation while reading. A computer-based eye-movement controlled display system was developed to examine how visual information is processed during reading. The study involved modifying text patterns based on eye position and observing the effects on eye behavior. Results indicated that word-length pattern information was acquired at least 12 to 15 character positions to the right of the fixation point, primarily influencing saccade lengths. Specific letter- and word-shape information was acquired no further than 10 character positions to the right of the fixation point. Psychologists have long been interested in how much can be read in a single fixation. Previous studies have shown that the amount of information that can be seen and reported from a single fixation varies depending on the type of material and presentation conditions. However, these studies do not fully address the question of how far into the periphery specific aspects of the visual stimulus are acquired and used during reading. The research here aimed to develop a method to determine the size of the region from which specific types of visual information are obtained during reading. An eye-movement controlled display system was used to modify text based on eye position, allowing subjects to read normally while the system tracked their eye movements. The study involved varying window sizes and peripheral text patterns to determine how far into the periphery visual information was acquired and used. The results showed that word-length pattern information was acquired at least 12 to 15 character positions from the fixation point, while specific letter- and word-shape information was acquired no further than 10 character positions. The number of regressions and saccade lengths were influenced by the peripheral text patterns, with smaller window sizes leading to more regressions and longer fixations. The study also found that reducing the window size did not affect comprehension test scores, suggesting that a reduced perceptual span does not necessarily lead to reduced comprehension. The findings suggest that during fluent reading, visual information is primarily acquired from a relatively narrow region, and that word-length patterns are acquired further into the periphery than specific letter and word-shape information. The study also indicates that the perceptual span during reading may not be symmetrical around the point of central vision. The results highlight the importance of peripheral visual information in guiding eye movements during reading and suggest that manipulating display based on eye-position information may help in understanding the perceptual span during reading.This study investigates the region from which skilled readers acquire visual information during a fixation while reading. A computer-based eye-movement controlled display system was developed to examine how visual information is processed during reading. The study involved modifying text patterns based on eye position and observing the effects on eye behavior. Results indicated that word-length pattern information was acquired at least 12 to 15 character positions to the right of the fixation point, primarily influencing saccade lengths. Specific letter- and word-shape information was acquired no further than 10 character positions to the right of the fixation point. Psychologists have long been interested in how much can be read in a single fixation. Previous studies have shown that the amount of information that can be seen and reported from a single fixation varies depending on the type of material and presentation conditions. However, these studies do not fully address the question of how far into the periphery specific aspects of the visual stimulus are acquired and used during reading. The research here aimed to develop a method to determine the size of the region from which specific types of visual information are obtained during reading. An eye-movement controlled display system was used to modify text based on eye position, allowing subjects to read normally while the system tracked their eye movements. The study involved varying window sizes and peripheral text patterns to determine how far into the periphery visual information was acquired and used. The results showed that word-length pattern information was acquired at least 12 to 15 character positions from the fixation point, while specific letter- and word-shape information was acquired no further than 10 character positions. The number of regressions and saccade lengths were influenced by the peripheral text patterns, with smaller window sizes leading to more regressions and longer fixations. The study also found that reducing the window size did not affect comprehension test scores, suggesting that a reduced perceptual span does not necessarily lead to reduced comprehension. The findings suggest that during fluent reading, visual information is primarily acquired from a relatively narrow region, and that word-length patterns are acquired further into the periphery than specific letter and word-shape information. The study also indicates that the perceptual span during reading may not be symmetrical around the point of central vision. The results highlight the importance of peripheral visual information in guiding eye movements during reading and suggest that manipulating display based on eye-position information may help in understanding the perceptual span during reading.