more tutorials:

vampire makeover
light explosion text.
Ice text.
Glass text effect.
Bloody text.
Create realistic vampire fangs.
Create a Smoky Eye make up.
Changing Eye color and eye retouching.
change hair color.
Making dark and cold photo effect.
Creating ghost photo.
Drawing fake blood.
Create forum signature in photoshop.

Changing Eye color and eye retouching in photoshop.

This tutorial shows eye retouching techniques, it has 3 parts:

Adding Highlights to the iris.

step 5

Make a new layer by clicking the create a new layer icon in the layer window or going Layer > New > Layer.
crate new layer

Change the layers blend node to Overlay
schange blend mode

Choose the Brush Tool brush tool
Select a brush about one third of the iris size,
with its hardness set to 0%.
And Opacity set to 15%

Stroke with white couple times around the iris.

The brush work doesn't have to be even, actually it looks better when some parts are brighter then others.
Here's a picture that shows how I used the white brush (change the blend mode to normal to see this), The upper-right part of the iris is very white, and there is also a reflection on the buttom-left.
high ligths

Back to Overlay mode,
This is my final result.
final result