Accommodative insufficiency is the premature loss of accommodative amplitude. This problem may manifest itself by blurring of near visual objects (as in presbyopia) or by the inability to sustain accommodative effort. The onset may be heralded by the appearance of asthenopic symptoms; the ultimate development is blurred near vision. Such “premature presbyopia” may signify concurrent or past debilitating illness, or it may be induced by medications such as tranquilizing drugs or the parasympatholytics used in treating some gastrointestinal disorders. In both cases, the condition may be reversible; however, permanent accommodative insufficiency may be associated with neurogenic disorders such as encephalitis or closed-head trauma. In some cases, the etiology may never be determined. These patients require additional reading plus power for near vision. The most common causes of premature presbyopia, however, are unrecognized (latent) hyperopia and overcorrected myopia.
Excerpted from BCSC 2020-2021 series : Section 3 - Clinical Optics. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.