Forced vergence fixation disparity curves at distance and near in an asymptomatic young adult population.

Forced vergence fixation disparity curves were measured at distance and near on an asymptomatic young adult population (average age 24.7 +/- 5.2 years, range 14 to 35). Approximately 60% of the 62 subject sample had the same curve types at distance and near (type I, 50%, type II, 9.7%). Unlike curves were found in 40.3% of the sample. Detailed breakdown of the unlike curve types is provided, along with a discussion of the results. Clinical implications of the necessity to establish normative data for fixation disparity curves at distance and near for different vergence states, age groups, and symptomatic patients are stressed.