Weak Accommodation in Asymptomatic Young Adults

Abstract

Weak accommodative function does not always predict visual discomfort symptoms during near work (Chase C, Tosha C, Borsting E, Ridder WH. Visual discomfort and objective measures of static accommodation, Optom Vis Sci 2009;86:883-89). This study examined the possibility that individuals with weak accommodation may remain asymptomatic through a compensatory vergence response. Both binocular and monocular continuous autorefraction data was collected using a Grand-Seiko WAM-5500 autorefractor while young adults read a passage from a children’s story for 10 minutes. Participants’ scores on the Conlon survey (Conlon EG, Lovegrove WJ, Chekaluk E, Pattison PE. Measuring visual discomfort. Vis Cogn 1999;6:637-63) provided a measure of their visual discomfort. For some of the participants with low near work visual discomfort, accommodation lags in the monocular and binocular conditions were comparable and well within depth of focus. However, there was a subset of asymptomatic participants who exhibited a large lag outside the depth of focus in the monocular condition that decreased in the binocular condition. This may be due to a strong vergence system that compensated for weak accommodation. When they perform a binocular task such as reading in a natural setting, their vergence system affords them the ability to perform near work with relatively little discomfort even though they do not have a strong accommodative response. Objective measures of accommodation, such as autorefraction, can identify asymptomatic individuals who have weak accommodative function by comparing the accommodation lag during binocular and monocular tasks. Meeting abstract presented at VSS 2012