Premium
The effect of vergence adaptation on convergent accommodation
Author(s) -
Rosenfield M.,
Gilmartin B.
Publication year - 1988
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1111/j.1475-1313.1988.tb01033.x
Subject(s) - accommodation , vergence (optics) , adaptation (eye) , optometry , psychology , computer science , medicine , computer vision , neuroscience
This study investigates whether, during a sustained near‐vision task, the convergent accommodaton (CA) derived initially form the fast (reflex) vergence response is subsequently maintained by tonic (adaptive vergence. CA was examined during the course of a 3 min near‐vision taks (viewing distance 33cm) in 10 emmetropic subject. Vergence was stumulated by the introduction of a 6δ base‐out prism before the right eye while the open‐loop accommodative response of the left eye was measured at approximately 1 s intervals using an objective infra‐red optometer. In a control condition the subject viewed the target through a plano lens (Oδ) The accommodation loop was opened by the subject viewing near‐type through 0.5 mm diameter pinholes. Pre‐ and post‐task measurement of heterophoria was made using a Maddox rod and prism bar. Regression of post‐task heterophoria to the pre‐task value indicated that adaptation to the vergence stimulus had occurred. However, there was no significant reduction in induced CA during the task. As the onset of adaptation does not produce any fall in CA, it is concluded that both reflex and adaptive vergence act as a stimulus to CA. This finding is discussed with regard to models of accommodation‐vergence interaction.