Check out this tutorial and enhance your images. So lets start.
1. Open your picture. File>Open.

In my tutorial im gonna use Mr.Potter as our model picture.

2.Choose Elliptical Marquee Tool (M).

3.Select the Eye portion of the picture. Hold Shift while your selecting.

4.Now go to Image>Adjustments>Hue/Saturation or CTRL+U for shortcut command.Adjust Hue to -50.

5. After you adjust the Hue it will look something like this.

Well done!!!!now you learn how to change eye color…