PMC

Left: accommodation response as a function of vergence distance, accommodation distance (red: 0.57 m, blue: 0.8 m and black: 1.33 m, circle: no conflict) and distance conflict (square: ± 0.5 D, triangle: ± 1 D). Middle: vergence response as a function of vergence distance, accommodation distance, and distance conflict (same legend). Negative responses indicate disaccommodation or divergence response functions whereas positive responses indicate accommodation or convergence response steps. Right: accommodation and vergence response amplitude as a function of distance conflict. Accommodation is depicted in dark orange and vergence in dark blue. Vertical error bars show 95% Cousineau-Morey confidence intervals for within-subjects designs (Cousineau, ; Morey, ).

Relationship between the amount of accommodation and the initial vocal distance of each pair for phee-, trill-, and food calls. Significant changes in vocal distances are indicated with an *. Positive accommodation indicates convergence, i.e. that the pair became more similar, negative accommodation indicates divergence. For both trill calls and food calls, the amount of accommodation was predicted by the initial distance.

Accommodation and vergence response amplitude as a function of perceived depth difference (dark orange: accommodation, dark blue: vergence). Lines represent linear regression fit. Note that negative values refer to divergence or disaccommodation, while positive values refer to convergence or accommodation.

Example of the change of 4th-order spherical aberration with accommodation in a young subject with an AA > 12.00 D. In the relaxed eye the value is positive decreasing with accommodation and becoming negative. For large values of accommodation demand, spherical aberration tends to zero because the subject’s pupil becomes small.