Age-related changes in optokinetic and rotational tests.

Optokinetic nystagmus (OKN) and nystagmus induced by the rotational test were analyzed in sixty normal subjects, 13 to 68 years old. Reactivity was measured by the maximum slow phase velocity. A slight linear correlation to age was found in both tests. In the OKN test the eye speed increased with advancing age, and in the rotational test the eye speed decreased with advancing age. This pattern was found statistically significant at a target speed of 40 degrees/s in the OKN test and at 6 degrees/s2 (stimulation) in the rotational test.