This study examined whether one can differentiate between areas of known visual field loss and areas of known relative field sparing in eyes with primary open angle glaucoma using motion coherence thresholds. Two visual field locations from patients with primary open angle glaucoma (n = 14), which differed significantly in sensitivity, were selected for presentation of a motion stimulus. In the area of visual field loss mean threshold was 17.4 +/- 4.1 dB (1.74 +/- 0.41 log units relative to the brightest stimulus). In the area of relative field sparing mean threshold was 27.0 +/- 3.6 dB (2.70 +/- 0.36 log units). Motion coherence thresholds were significantly poorer for the area of visual field loss compared to the area of relative field sparing (P < 0.0032, two-tailed paired t-test). This result suggests that a perimetric type motion test should be evaluated for early detection of glaucoma.