Adobe Tutorial

1. Select Background layer in layers palette
2. Select the complete eye area ( including the white part ) using any selection tool (i used quick selection tool). Right click over the selected portion and say Layer via Copy. Name this layer in layers palette as Eyes by double clicking the layer in the palette.
3. Now select the background layer again and make a selection for the eye ball regions only. And right click and select Layer via Copy and name this layer as Eye ball.
4. Now Conrol+Click on the layer Eyes to show the eyes selected in the image. Click on Background layer and Select Inverse from right click on image area followed by Layer via Copy. Name this new layer as Blur. This constitutes the whole image except the eye region.
5. Now select the layer Blur and Filter>Blur>Gaussian Blur. Modify the blur to something like 2.5 or lesser. This is done to rest of the image leaving eyes so that eyes are prominent in the image. Click Ok. You can later on modify the opacity of the layer making it more transparent if you want to decrease the blur effect. You can do that by selecting this layer in the layer palette and moving the opacity slider on right top of layers palette.
6. Now select the layer Eyes. Go to Enhance>Adjust Sharpness. Now make changes to the amount and radius. Click Ok. You can vary the sliders as per your needs and preview it side by side in image area or preview area in the dialog. Do not oversharpen as it makes the eyes look artificial.
7. Now select only the layer Eye ball and select Enhance >Unsharp mask.
I changed the amount to near 50% and radius to near 16. This details out the pattern inside the eye ball and brings more focus to the eye region.
8. You can now also increase the saturation of this layer by Enhance>Adjust color>Adjust Hue/Saturation. You can select the Grrens from the combo box if you obly want to saturate the Green of the eyes using the Saturation slider.
Click Ok.

Here are the initial and the final images :