How to change the eye colour in 3 simple steps 12/02/2016
Using the Elliptical Marquee Tool, create a selection around the eyes. Remember, holding down the "shift" key will keep these selections as perfect circles, as well as letting you create more than one.
Since we don't want to affect the upper part of the selection, let's deselect it by holding down the ALT key (in order to "subtract" from the selection) and drawing around the unwanted area with the Lasso Tool ("L" on the keyboard).
Once we have a election around the pupils, we go and add a Hue/Saturation Adjustment Layer from the adjustments panel. Having the previous selection will active will automatically create a mask on this adjustment layer. Now we can change the hue of the eyes to any colour we like.