presbyopia

Presbyopia (from Greek presbys (πρέσβυς) = old man + ops (ὤψ) = see like, sight > meaning literally trying to see as old men do) is a condition associated with aging in which the eye exhibits a progressively diminished ability to focus on near objects. Presbyopia’s exact mechanisms are not fully understood; research evidence most strongly supports a loss of elasticity of the crystalline lens, although changes in the lens’s curvature from continual growth and loss of power of the ciliary muscles (the muscles that bend and straighten the lens) have also been postulated as its cause.