Definition
An age-related vision change in which the lens of the eye gradually loses flexibility, reducing the eye's ability to focus on close objects. It typically becomes noticeable after age 40 and is corrected with reading glasses, bifocals, or progressive lenses.
Plain English
As people get older, their eyes have a harder time focusing on things up close, like a chart or instrument panel. It's a normal part of aging, not a disease.
Context Anchor
Seen in night vision and pilot health discussions, especially when reading cockpit information in low light.
Derivation
From Greek 'presbys' meaning 'old man' and 'opia' meaning 'sight' or 'vision.' Literally 'old-person sight,' which describes exactly what it is: the change in close-up vision that comes with age.
Why Pilots Care
It impairs reading approach plates, checklists, and instruments at night or in dim cockpit lighting, raising the chance of misreading critical information.
Grounding Statement
A pilot with presbyopia may see the runway lights clearly in the distance but struggle to read a nearby chart or panel label.
Intuition Check
Presbyopia is not simple tired eyes from one long flight. It is a normal age-related change in near vision that usually needs correction.
Example Sentence 1
After turning 45, the pilot noticed presbyopia made it harder to read the approach chart without reading glasses.
Example Sentence 2
Many experienced pilots carry reading glasses to counteract presbyopia when checking fuel gauges or setting the altimeter at night.