Made in PSP7 should be easy to translate in other versions
Going from THIS
to
WARNING: IMAGE HEAVY
Right so we shall beging....."
Were going to make a similar icon like this just with a different picture

Im using THIS
picture of the lovley Angelina Jolie.
1. Open you image, first were going to crop her eye like so
. Then crop it to 100 x 80 Duplicate it Effects>>Sharpen and Unsharpen Mask set it to screen then Layers>>Merge>>Merge(all flatten) and add a black border 
2. Now with the same image we are going to crop it and resize to 100 x 100

3. Now were going to add some textures to our 100 x100 picture.
I'm using this
texture by
I made a new layer and added a brush by
and set it to soft light Opacity 1003. Now re-open you eye and click Edit>>Copy and Paste it on to you 100 x 100 base and it should look like this.
Now were going to add anthoer texture by
and set it to Hard Light opacity 75Create anthor Layer, I added this
brush made by
and set it to soft light merge all layers add a border and hey presto :) 