Changes may start in our 30s, but accelerate in our mid-50s. Peripheral vision shrinks; we have trouble seeing objects clearly at different distances and in dim light; correctly judging distances; distinguishing certain colors.

By understanding how our bodies change over time, we can do a better job of designing our built environment to accommodate a broader range of physical abilities.


Strength and endurance diminish over time, beginning with loss of muscle mass around age 30. As muscles become weaker, more rigid, and less flexible, movement and gait become slower, more limited, and unsteady; fatigue occurs sooner. All these changes increase the risk of injury.


Maximum lung capacity may decrease as much as 40% between the ages of 20 and 70.


As we age, reduced skin sensitivity may affect our ability to distinguish changes in temperature or movement, to feel pain, and to react to different stimuli.


Bone replacement slows with age, reducing density and making bones more susceptible to fracture — occurring more quickly in women during and after menopause. Overall height often decreases as vertebrae become less dense, curving and compressing the spinal column into a stooped posture.


Gradual hearing loss starts in our mid-40s. It becomes harder to hear higher frequencies — particularly when there’s background noise. One-third of people 65 to 74, and half of those over 75, experience significant hearing loss.

Brain & Nervous System

Subtle deficits in memory may start in our 40s. One third of people experience more significant loss by their 70s, after which 10%+ develop Alzheimer’s disease.


With less fluid to lubricate joints, cartilage erodes and joints become stiffer — particularly knee, hip, and finger joints — leading to pain, inflammation, stiffness, and sometimes deformity. Most people over 60 experience some joint problems, whether it’s minor stiffness or severe arthritis.

Illustration: Dan Page