AskDefine | Define presbyopia

Dictionary Definition

presbyopia n : farsightedness resulting from a reduced ability to focus caused by loss of elasticity of the crystalline lens with age

User Contributed Dictionary

English

Pronunciation

Etymology

From , from presbys "old man", and -opia (Definition on Merriam-Webster).

Noun

  1. Inability of the eye, due to ageing, to focus on nearby objects

Antonyms

Extensive Definition

Presbyopia (Greek word "presbys" (πρέσβυς), meaning "old person") describes the condition where the eye exhibits a progressively diminished ability to focus on near objects with age. Presbyopia's exact mechanisms are not known with certainty, however, the 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.
presbyopia in Catalan: Presbícia
presbyopia in Czech: Presbyopie
presbyopia in Spanish: Presbicia
presbyopia in French: Presbytie
presbyopia in Italian: Presbiopia
presbyopia in Dutch: Oudziendheid
presbyopia in Japanese: 老視
presbyopia in Polish: Presbyopia
presbyopia in Portuguese: Presbiopia
presbyopia in Romanian: Prezbitism
presbyopia in Swedish: Ålderssynthet
presbyopia in Chinese: 老花
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