Figure 7. Methods.

(A) Implanted baseplate with magnetic attachment point and restraining pin holes. (B) Miniaturized eye cameras and head position tracking system. Infrared illumination LEDs were mounted on the camera objective and reflected onto the eye using an IR-reflective mirror. Head position tracking IR-LEDs were mounted on three carbon-fiber struts attached to the head-mount. (C) Cricket capture times in lit or dark conditions in mice without (n=19 pursuit sequences, n=6 mice) or with (n=10 pursuit sequences in lit conditions and n=9 pursuit sequences in the dark, n=3 mice) corneal TiO₂ torsion tracking spots, Lit vs Dark with no spot, p = 0.0012, Lit vs Dark TiO₂ spot, p = 0.0133, Lit without spot vs Lit with TiO₂ spot, p = 0.69, Dark without spot vs Dark with TiO₂ spot, p = 1. n.s. = non-significant, *p<0.05, **p<0.01. Paired Wilcoxon’s signed rank tests. For these experiments, pursuits were conducted in a smaller arena (480 x 375 x 210 cm). (D) Images of mouse with eye camera and head position tracking system for anatomical calibration. Head mount and anatomical features marked. Anatomical features: Left (blue filled circles) and right (green filled circle) medial canthi, left (orange filled circles) and right (red filled circle) nostril positions. Head mount features: position tracking LEDs (large colored circles), IR mirror corner positions (small colored filled squares). (E) Sensitivity of the radial elevation on the retina in the mouse eye model to changes in the radii of curvature and thicknesses of the model optical components.