Fig. 2

The dual Y-axis charts of both functional visual acuity (FVA) and objective scatter index (OSI) values measured by the simultaneous real-time analysis system. The solid line with dots is the FVA curve, and the solid line with triangles is the OSI curve. a A dual Y-axis chart of a participant in the dry eye group, the visual acuity break-up time (VA-BUT) was defined as the time between blink and the observation of visual acuity first decreased by two lines or more (red arrow). The OSI break-up value (OSI-BUV) was defined as the OSI value corresponding to the visual acuity break-up time (VA-BUT) in the dual Y-axis chart. For this participant, the VA-BUT is 6.6 s and the OSI-BUV is 0.89; b A dual Y-axis chart of a participant from the normal control group. No decrease of visual acuity for more than two lines was noted. The VA-BUT was set to 20 s and the OSI-BUV was defined as the OSI value of the last measurement. For this participant, the VA-BUT is 20 s and the OSI-BUV is 0.51; c The dual Y-axis charts of both FVA and OSI values in intervals of 0.5 s for 20 s. In the DE group, the OSI demonstrated a more pronounced ascending pattern over time than NC group, while the FVA demonstrated a pronounced and corresponding descending pattern. Error bars represent standard deviation. BCVA, best-corrected visual acuity; DE group, dry eye group; NC group, normal control group