A method for operating an assist system for a vehicle that includes a sensor device for detecting a directional characteristic value that is representative of a viewing direction of a driver of the vehicle. In the method, a calibration characteristic value is provided that is representative of a rest viewing direction of a standard driver. At least one initial direction characteristic value is determined, in dependence of which a rest characteristic value is determined that is representative of a rest viewing direction of the driver. A transformation characteristic value is determined based on the rest characteristic value, which is representative of a transformation between the rest characteristic value and the calibration characteristic value. Based on the transformation characteristic value, subsequently determined directional characteristic values are corrected.