What term describes the difficulty to focus on close objects due to a change in lens shape?

The term that describes the difficulty in focusing on close objects due to a change in lens shape is presbyopia. This condition typically arises with age, as the lens in the eye becomes less flexible and loses its ability to change shape effectively. This loss of flexibility means that the lens cannot adequately accommodate for near vision, resulting in the challenge of focusing on objects that are close.

Presbyopia is distinct from other vision issues, such as cataracts, which involve the clouding of the lens, leading to blurred vision but not directly related to lens shape changes. Tunnel vision refers to a loss of peripheral vision but does not involve issues with focusing on close objects. Macular degeneration affects central vision clarity rather than focusing ability in general. Each of these conditions has different underlying mechanisms and symptoms, but presbyopia specifically pertains to the challenge of reading or seeing nearby objects clearly due to lens rigidity.