Anesthetized animals received 1% tropicamide and 0.5% proparacaine drops to the eye contralateral to the implanted V1 electrode (n = 5, 5, and 3 for P120, P180, and P360, respectively). The W2100-HS14-ES2-0.5 mA headstage (MCS Pharma, Hamburg, Germany) was connected to the animal. The animal was dark adapted for at least 5 minutes before recording. Before recording, a 9000K white LED (C5030-WAN-CCBEB151-ND; DigiKey, USA) was placed approximately 1.5 cm away from the dilated eye. The LED had a 181 mW/cm2 steady-state ON irradiance measured using a photodiode sensor set at 535 nm, set 1.5 cm away from the LED (PM16-130; Thorlabs Inc., Newton, NJ). A drop of BSS was applied to the eye and siphoned with a surgical spear to hydrate and clean the eye before stimulation. If the eye was not readily proptosed (in the case of isoflurane anesthesia, rarely of ketamine/xylazine anesthesia), then a speculum (WPI, Worcester, MA) was used to retract the eyelids and expose the eye. Flash stimulation of the retina was done with 10 ms pulse duration of 1 or 10 Hz frequency, with 100 or 300 pulses, respectively. For a subset of animals, the eye ipsilateral to the implanted V1 electrodes were also stimulated as a negative control.