Maybe you could use a black & white image as a variablereflections  fonction, try any interior photo with a strong light coming from a window, the window would ideally be in the center of the photo,  turn it b&w with a very strong contrast and use it as a variable reflections function. Or paint a b&w image yourself. Then use an hdr file for lighting your scene, the hdr will reflect in the eyes according to the image you loaded as a variable reflections function.