<p>Peripheral vestibular disorders (PVDs) are frequently encountered in clinical practice. The optokinetic after nystagmus (OKAN) test may help differentiate between central and peripheral vestibular disorders. This study aims to evaluate OKAN patterns and OKN gain, and assess their significance in distinguishing central vertigo from peripheral vertigo. A prospective observational study was conducted with 138 participants. Ninety-two patients clinically diagnosed with either central or peripheral vestibular disorders were enrolled in the study, while 46 healthy volunteers were included as controls. VNG, including OKAN testing and OKN gain measurement, was performed on all participants. The study group was split into those with central vertigo (Group A, 32.6%) and those with peripheral vestibular disorders (Group B, 67.4%), with the control group serving as Group C for comparison. OKAN patterns were classified into six types based on the Arai et al. classification. Differences in OKN gain between groups were analyzed. The most common OKAN pattern observed was Type 3 in all three groups (central, peripheral, and control), with frequencies of 56.7%, 53.2%, and 67.4%, respectively. However, the mean OKN gain was significantly lower in participants with central vertigo compared to those with peripheral vertigo. While OKAN patterns did not reliably distinguish between central and peripheral vestibular disorders, individuals with central disorders demonstrated a significantly reduced OKN gain, which may serve as a useful clinical marker.</p>