A system comprising: an illumination system configured to illuminate an eye; a camera (32,34) configured to acquire one or more images of the eye; and operatively coupled to the camera (32, 34) and the illumination system, a processor and associated computer memory, the computer memory holding instructions executable by the processor to obtain a series of three or more images, the images acquired by the camera (32, 34) at different levels of illumination of the illumination system; analyze the obtained images and select first and second images from the series of obtained images which exhibit saturated eyeglass reflections and strong but unsaturated bright pupil reflections, wherein distinguishing eye from eyeglass reflections includes comparing the brightness of corresponding pixels of a first image acquired at the first level of illumination and a second image acquired at the second level of illumination, associating the corresponding pixels with the reflection of the illumination by the eye if the brightness of such pixels differs by more than a threshold amount and associating the corresponding pixels with the reflection of the illumination by the eyeglass if the brightness of such pixels differs by less than a threshold amount; obtain refined first and second illumination levels based on the selected first and second images to distinguish a reflection of the illumination by the eye from a reflection of the illumination by an eyeglass; and furnish input representing gaze direction to the computer system based on the reflection of the illumination by the eye and independent of the reflection of the illumination by the eyeglass. an illumination system configured to illuminate an eye; a camera (32,34) configured to acquire one or more images of the eye; and operatively coupled to the camera (32, 34) and the illumination system, a processor and associated computer memory, the computer memory holding instructions executable by the processor to obtain a series of three or more images, the images acquired by the camera (32, 34) at different levels of illumination of the illumination system; analyze the obtained images and select first and second images from the series of obtained images which exhibit saturated eyeglass reflections and strong but unsaturated bright pupil reflections, wherein distinguishing eye from eyeglass reflections includes comparing the brightness of corresponding pixels of a first image acquired at the first level of illumination and a second image acquired at the second level of illumination, associating the corresponding pixels with the reflection of the illumination by the eye if the brightness of such pixels differs by more than a threshold amount and associating the corresponding pixels with the reflection of the illumination by the eyeglass if the brightness of such pixels differs by less than a threshold amount; obtain refined first and second illumination levels based on the selected first and second images to distinguish a reflection of the illumination by the eye from a reflection of the illumination by an eyeglass; and furnish input representing gaze direction to the computer system based on the reflection of the illumination by the eye and independent of the reflection of the illumination by the eyeglass.