Abstract
Aging is associated with changes in visual function, even in the absence of ocular pathology. While visual acuity remains largely intact, older individuals frequently report difficulties with real-world visual tasks. One potential contributing factor is visual crowding, the inability to recognize a target in the presence of surrounding clutter. Although peripheral crowding has been widely studied, foveal crowding was once considered controversial and has only been observed under specific conditions. Its relationship with aging, however, remains poorly understood. This study investigates the impact of aging on foveal crowding under both unlimited and limited viewing conditions. Thirty-three participants (ages 20-89) completed a letter recognition task with varying target-flanker spacing. Under unlimited viewing conditions, crowding effects were insignificant across age groups. However, when a brief presentation time was introduced, older participants exhibited a significantly greater crowding effect, with a pronounced decline in visual acuity. Reaction time also increased with age, particularly in the unlimited viewing condition, where older adults took longer to respond despite maintaining high accuracy. These findings suggest that aging primarily affects foveal crowding under time-limited conditions, likely due to declines in processing speed. The results highlight the importance of considering temporal constraints in visual assessments of older adults, with potential implications for daily activities such as reading and driving.