Changing eye color in Photoshop

So here is a real easy and effective way to change eye color on a shot, from brown to blue.
1. Switch to 'Quick Mask' mode - press the 'Q' button
2. With a soft bush, paint the area you'd like to select
3. Hit the 'Q' button to escape quick mask mode
4. From your adjustment layers panel, open 'Selective Color' and choose Neutral from the drop down window
5. Lower the sliders on magenta and yellow
6. Make a selection from the previous adjustment layer
7. Go to Hue/Saturation and select 'Cyans' from the drop down window and adjust to your liking
8. You are done

There are other ways to do this, as with everything in PS. This is just one way. If this doesn't work for you, try using curves to lower the reds and yellows, or try channel mixer, or color balance. There's a dozen different methods for this. Try to work out which one is best for you.