Photoshop Move Tool

The Move tool (shortcut M) is used to move the selected area of an image or the image (layer) itself unlike moving the selection which we did in Marquee tools > Moving the selection. This is best explained practiaclly.

Lets select the left eye of this cute model. We'll use Elliptical Marquee Tool.

Now making sure that the Move Tool (shortcut V) is selected on the tool box (the cursor should be an arrow with a scissor), drag the selected elliptical area to another region. (shortcut Ctrl + drag when any other tool is selected). To perform perfect horizontal or vertical move, click shift, so that makes it Ctrl + Shift + drag.

Voila!! the eye is shifted to the cheek of the girl. Notice the white region left behind in the eye. It is white because the background color currently assigned is white (and the foreground is black, look below).

You might be wondering to move the eye, keeping the original eye in its own place, in other words "Duplicating" the eye. This can be done by clicking Alt key while you drag. Notice the move cursor change to duplicate cursor when you press Alt. See below:

To finish the move process, press Ctrl+D and you're done with a girl having three eyes, one on her cheek .

You can use Keyboard arrow keys to move more precisely to any direction you want, hold shift key to move in larger scale. Pressing Alt key works in this method too. Give it a try.

To learn more about moving with smooth edges go to this tutorial > Edge Feather.