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 five near/distance stereotests drawn from a large sample 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 (FD2, 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