As aging societies enter worldwide, the elderly population is increasing year by year, and visual and cognitive impairment have thus become important global issues, imposing a significant socioeconomic burden worldwide. In recent years, a large number of studies have shown a strong association between visual and cognitive impairments, with patients with visual impairment being more likely to experience cognitive decline, especially dementia. In addition, there is also evidence that improving visual acuity has a significant effect on cognitive function, and that by improving visual function, the development of cognitive decline and dementia can be delayed, which provides new ideas for public health efforts to delay and mitigate cognitive decline and dementia by improving visual function. The possible mechanisms underlying the association between visual and cognitive impairment remain unclear and need to be studied further.