Abstract
Purpose :
The current understanding of binocular processing is primarily derived from static spatial visual perception: this leaves the role of temporal information unclear. In this study, we addressed this gap by testing the effect of alternating flicker on binocular information processing in adults with both induced and congenitally abnormal binocular vision. Our goal was to determine which temporal frequency optimally balanced input from both eyes.
Methods :
We took measurements in four groups of human adults: 10 normal adults with individual’s non-dominant eye covered by a 2% ND filter (25.60 ± 1.43 years, Experiment 1), 9 non-amblyopic anisometropes (24.33 ± 1.66 years, Experiment 2), 7 amblyopes (26.5 ± 1.64 years, Experiment 3), and 7 treated amblyopes (24 ± 3.21 years, Experiment 4). The balance point (BP), where observers’ two eyes are equally effective, was measured using a binocular orientation combination task at 4 spatial frequencies (SFs, 0.5 - 4 c/d) and 5 temporal frequencies (TFs, baseline, 4,7,10,15Hz). Its log transformation |logBP| was taken into further analysis.
Results :
We observed clear U-shaped temporal tuning of the |logBP| for the entire range of TFs (that we measured: trough occurred at 7 Hz. This pattern occurred, and was significant, in all four groups (P< 0.001). In addition, the effect of SFs on |logBP| was significant in normal, amblyopic, and treated amblyopic groups (all P < 0.001), and was marginally significant in the non-amblyopic anisometropic group (P = 0.086).
Conclusions :
Alternating flicker around 7Hz may be the optimal temporal frequency for balancing eyes in human adults with binocular imbalance.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.