People have a strong ability to adapt to the changes of light. And light changes in the natural environment is inevitable. In the past we have proposed eye-vergence visual servoing system. However we did not know how it performs in dark or bright environment. If a visual servoing system has a higher light environmental robustness it will have a wider range of application. Therefore we design tracking experiments under different illumination and partial occlusion condition. Though the experiment it is verified that the system is not easily affected by ambient brightness and can continually track the object. Compared with the partial occlusion condition, the influence of changing of light condition is smaller.