a few ways to do it
1 way.. Blue Fringe is only in blue channel.. so..
1) Then we open the Channels pallet (menu<Window<Channels) and select the blue channel only, select the whole thing, copy it out into a new document.
2) select the fringe + bright area, duplicate (Ctrl + J) into a new layer, set the mode to multiply
3) merge the whole thing, copy it and past it back into the blue channel of the original image.