There are many applications of the robust eye states detection. In this paper

five methods are applied to detect the eye states in color eye images. They are gray model method

fisher method

projection method

detect-upper-eyelid method and detect-eyeball method. Each of the five methods has its advantage as well as its disadvantage. To increase the accuracy of detection

a combined method is proposed

which combines the above five methods so that it can take good advantage of them all. Experiments are done with 396 different human eyes

264 of which are closed ones

and 377 of these experiments turned out satisfactory results. The accuracy reaches 95. 2 %. The inspiring outcome shows that the combined method is effective even if the illumination is nonlinear. At the same time

the combined method is practical because it is moderate in both time and space consuming. This paper introduces in details the idea of the five methods

the design of the combined algorithm

the experiments and their relevant results.