Select the emus eyes in the mask editor using similar techniques to those discussed in This tutorial. The mask colour was set to magenta, the eyes selected using the brush tool and magic wand and then feathered.
When selecting a region using the brush tool holding ALT down will make a circle appear over
the mask which indicates how large the brush is and which mask pixels will be affected by it. By varying the size, opacity and softness of the brush this allows very fine control. The almost invisible birds left eye (obscured by eyelashes) was selected using the magic wand with a slightly lowered 'Adding' tolerance.
In the thumbnail variations window click on View to open a full view onto the image and then on the emus right eye in the image. The variations thumbnails will all change to show this region of the image at 100 percent.
As you can see, the mask has confined the saturation shift to the birds eyes, allowing you to make changes to that region of the image without affecting any others. Try switching to hue shift mode and
recolouring the birds eyes: