How to transform brush strokes?

[WagsFresh]

So... Dont laugh... I have drawn an image/shape with the brush (stroke no fill) and I want to select it, copy it and reflect it horizpntally so I have an exact mirror copy (its an eye so im going for symmetry here) It is on its own layer with the rest of the line art. 

Thank you a million times!!!

Image attached

[Semaphoric]

Drag out a guide to the center of the face. Drag out a rectangular selection from that guide, enclosing the eyes. Free Transform a copy (Alt+Control+T), setting the reference point to middle left,  and horizontal scaling to -100%.

[c.pfaffenbichler]

I would recommend a Smart Object approach. 

Cut the pertinent Elements to a Layer of their own, convert to Smart Object, duplicate, flip and reposition. 

Are you familiar with Symmetry Painting? 

https://helpx.adobe.com/photoshop/using/paint-symmetry.html

[Trevor.Dennis]

Hmmm... you beat me to it c.p.

[c.pfaffenbichler]

The advantage of Smart Object instances in this case is that changes update in all the instances.