Accommodation response and visual discomfort.

Although visual discomfort symptoms associated with near work have been correlated with clinical measures of accommodation, studies using objective recordings have not found corresponding deficits in accommodative function. One problem with previous studies is that accommodation measures have been too brief to assess accommodative fatigue. This study examined steady state accommodative responses among a college population with visual discomfort, over a 90-s time period. Thirty-one participants were grouped into high (n = 15) or low visual discomfort groups (n = 16) based on their scores on the Conlon Visual Discomfort Survey. Using the WAM-5500 autorefractor, accommodation responses were recorded at 5 Hz for two consecutive minutes at five viewing distances. The results showed a significant interaction between the high and low discomfort groups over time in accommodation response. The high discomfort group showed an increase in accommodative lag, whereas the low discomfort group had a stable response. Our study suggests that the high visual discomfort group is characterized by accommodative fatigue, with a higher lag of accommodation developing at a near viewing distance over time.