Accommodation insufficiency and fatigue have been associated with near work visual discomfort symptoms, but clinical measures of accommodation amplitude suggest insufficiency is uncommon and often not weak enough to cause symptoms. However, recent studies show that the clinical push-up test used to measure amplitude overestimates accommodative function. This study uses an open-field autorefractor to measure accommodative stimulus-response functions objectively in college students with and without near work induced discomfort symptoms.
Using a Grand-Seiko WAM 5500 autorefractor, 2 min recordings were made each at five viewing distances (0 to 5 D) to measure an accommodative response function. Visual discomfort symptoms were assessed using the Conlon survey.
A strong and positive correlation between accommodative lag and visual discomfort symptoms was found under near work conditions. The prevalence of accommodative insufficiency was much higher than estimated by clinical measures.
Accommodative insufficiency and fatigue should be defined and described by objective methods using extended viewing times to assess function.
†OD, MS, FAAO
‡OD, PhD, FAAO
Colleges of Optometry and Biomedical Sciences, Western University of Health Sciences, Pomona, California (CC), Jules Stein Eye Institute, University of California, Los Angeles, Los Angeles, California (CT), and Southern California College of Optometry, Fullerton, California (EB, WHR).
This research was supported by grants from the National Eye Institute (R15EY015922) and the College of Vision Development.
Portions of the study were presented as a paper at the College of Optometrists in Vision Development meeting in October of 2008.
Received October 26, 2008; accepted December 9, 2008.