Some people say that the third eye is a window into the 6th chakra. I say it is a cool effect you can do with Adobe Photoshop. Either way, here it is.
We are going to start with a nice pic of Angelina Jolie.
Step 1. Drawing the eye
Create a new layer and select the Clone Stamp Tool.
Clone Stamp Tool
The clone stamp tool enables you to copy a certain part of a picture into another area. First select the background layer. Hold the Alt key and click in the middle of the left eye's pupil. Now select the new layer and start drawing in the middle of the forehead just above the eyebrows - that is where the third eye is supposed to be. Draw just the left part of the eye. Now select the background layer again and repeat the procedure with the right eye. That way we get a fairly symetrical third eye.
Remove the edges with the Eraser Tool
Step 2. Changing the eye color
Select the Polygonal Lasso Tool and use it to select the iris. You can help yourself with zooming in a little.
Polygonal Lasso Tool
Select Image -> Adjustments -> Photo Filter and choose the options as they are in the image below: Blue color, 100% Density.
Step 3. Scaling
Click on Edit -> Free Transform -> Scale and shrink the eye a little. Hold Shift to maintain proportions.
Step 4. Screen
First lower the opacity of the Third Eye layer to about 75%. Then copy that layer so you will now have two layers with the third eye. For second layer select Screen instead of Normal (see image below). Now the eye will look a little more shiny.
Step 5. Blending Options
You can do wonders just playing around with layer's blending options. One example is this. Open the last layer's blending options (right click) and select Outer Glow. Set it's parameters as they are on the image below: 65% Opacity, 24px Size, 37% Range and 14% Jitter. Be sure to select the same Contour type that I have selected (see image below) as it is the key feature of this effect.