Aim and objective: To compare the pupil cycle time (PCT) measurements in study participants with different grades of primary open-angle glaucoma against normal study participants. Materials & Methods: 80 eyes of 80 study participants with primary open angle glaucoma group (Group I); 85 eyes of 85 healthy group study participants (Group II) were studied. All study participants underwent Ophthalmologic investigations and data were assessed by Chi-squared and Pearson correlation analysis. Results: In Group I study participants, the mean age was found to be 66.6 ± 8.4 and in Group II participants it was 63.1 ± 8.2 (p=0.400). In Group I study participants, 63.5% were female and in Group II study participants they were 56.2% (p=0.300). In Group I, the mean PCT was 956.5 ± 64.8 ms whereas in Group II it was 872 ± 35.6 ms(p=0.030). Statistical significant observation was seen for (PCT) and other variables like age (p=0.01), duration of glaucoma, BCVA, Ganglion Cell-Inner Plexiform Layer Thickness (GC-IPLT), and Retinal Nerve Fibre Layer Thickness (RNFLT). Conclusion: Pupil cycle time displayed a substantial association with optical coherence tomography (OCT) variables.