There is disclosed a method and system for generating retinal signal data. Calibration data corresponding to an individual may be received. A threshold impedance may be determined based on the calibration data. Retinal signal data corresponding to the individual may be received. The impedance of the circuit collecting the retinal signal data may be compared to the threshold impedance to determine whether the retinal signal data contains any artifacts. A portion of the retinal signal data corresponding to the artifacts may be removed from the retinal signal data.