Basically, that's not a PS effect. It's done in photography by focusing on something closer (your main focus) and in the background, light spots will continue to get out of focus the further they are from the focal of your picture. If you have light coming through a tree in the background etc, it will create the same effect.
Also can use various lights throughout cities etc, anything that creates a light source in an area OUT of focus will do this.
<span id="INSERTION_MARKER">http://i168.photobucket.com/albums/u165/carrieg96/cute%20pics/291055_2487986693093_1655476637_2309619_1504267281_o.jpg<span>
<span>how do you make all those blurred circles in the filter lens blur in photoshop? or do you use light room to do it?

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