Why does vision in dim light become more difficult with age?

As people age, the ability to see in dim light—often referred to as "night vision"—naturally declines. This reduction in sensitivity under low-illumination conditions is a common aspect of the aging process.1

Several physiological changes contribute to this difficulty:

• Pupil Size: The pupil tends to decrease in size with age, which limits the amount of light that can enter the eye. Because less light reaches the retina, vision in dim environments becomes less effective.1
• Lens Changes: The lens of the eye may undergo age-related changes, such as the development of cataracts, which can cause cloudiness and further interfere with light transmission and visual clarity.12
• General Sensitivity: Older individuals generally experience a reduced sensitivity to light compared to younger people, making it harder for the eye to adapt to and function in low-light settings.1

While these changes are a normal part of aging, increasing the level of illumination can often significantly improve vision for older adults.1