Computer user interface methods that utilize the user's gazes have been investigated recently.Thesemethods may enable us to operate computers without using a mouse,and improve the accessibility of computersfor users having disabilities on their hands.However,those methods using gazes also have a difficulty,because eyemovements often include involuntary ones and the users need to concentrate on controlling their eye movement.We propose a user-interface system that enables the user to control a computer without needing to use any point-ing devices.We discuss a way of detecting the three-dimensional eye locations using first Purkinje images,whichare images reflected on the eyes' corneal surfaces.Furthermore,we also demonstrate a prototype system that uti-lizes this eye location detection method and enables the user to operate commercial applications with only usingfacial movements and without a mouse.Finally,we present our experimental results and evaluate this method.