Final answer:
Older adults experience a decline in vision due to age-related changes, affecting their ability to navigate steps and curbs. This decline is part of the aging process known as senescence and begins in middle adulthood, worsening into old age. Healthy lifestyle choices can help mitigate some effects of aging on the ability to see.
Step-by-step explanation:
The question pertains to the decline in vision experienced by older adults due to age-related changes. This vision impairment often makes it more difficult to manage everyday tasks such as navigating steps and curbs. The decline is due to a variety of factors, including reduced muscle strength, slower reflex times, and sensory deterioration that begins in middle adulthood and continues into old age.
These physical changes are a normal part of the aging process, often referred to as senescence, and can be influenced by lifestyle factors such as exercise, nutrition, and overall health maintenance.
During late adulthood, the senses, including vision, decline significantly. This can affect the ability to judge distances and depth, which in turn causes difficulty when dealing with uneven surfaces like stairs. Cognitive impairments, such as those caused by Alzheimer's disease, can further exacerbate these physical limitations. However, staying active and leading a healthy lifestyle can help minimize some of these declines.