1) Open the picture you want to work on in Adobe Photoshop
.(click on image to enlarge)
2) select the elliptical Marquee tool ( the circle selection tool) and select only the lens of the first eye, move your mouse to the other eye , press shift and hold the button down while adding another circular selection to the other eye
.(click on image to enlarge)
3) if you have parts that are selected outside the lens it's not a problem, just select the polygonal lasso tool , press alt and hold the button down , select the parts that are selected outside the lens to remove the selection from these areas, do that for both eyes.
(click on image to enlarge)
4) press ctrl+U to bring out the hue and saturation dialog box, check the box next to colorize and then drag the sliders to get the color you want for the eyes , press ctrl+d to remove the selection and that's it