Normative Values for Near and Distance Clinical Tests of Stereoacuity

Purpose: Extensive literature exists on normative stereoacuity values for younger children, but there is less information about normative stereoacuity in older children/adults. Individual stereotests cannot be used interchangeably-knowing the upper limit of normality for each test is important. This report details normative stereoacuity values for 5 near/distance stereotests drawn from a large sample of participants aged 16-40 years, across 3 studies. Methods: Participants (n=206, mean age 22.18 +/- 5.31 years) were administered the following stereotests: TNO, Preschool Randot, Frisby, Distance Randot, and Frisby-Davis 2. Medians and upper limits were calculated for each test. Results: Upper limits for each stereotest were as follows: TNO (n=127, upper limit=120 '' arc), Preschool Randot (PSR, n=206, upper limit=70 '' arc), Frisby (n=206, upper limit=40 '' arc), Distance Randot (n=127, upper limit=160 '' arc), and Frisby-Davis 2 (n=109, upper limit=25 '' arc). Conclusions: Normative values for each stereotest are identified and discussed with respect to other studies. Potential sources of variation between tests, within testing distances, are also discussed.