Figured I'd make a topic to see if anyone else has this issue.
In a nutshell:
The Iris enhance adjustment brush doesn't work on the eyes if I begin/place the brush on the iris. I have to start the stroke outside of the eye (usually on surrounding skin) then paint back onto the eye to actually paint on it and make an adjustment.
This only began after the last update. Anyone else?
I have to start the stroke outside of the eye
Strange.! And I am not sure what you mean by this.
In my experience the "Iris Enhance" preset simply sets up all the adjustment sliders for brushing effects.
The Brush cursor can be re-sized or brushed anywhere on an image (as can any other brush)
It is possible you also have the "Auto Mask" option set on. Try the brush with this un-ticked.
Are you zoomed in on the eyes?
If the you aren't the pin you set with the first click could be covering the eye and not allowing you to actually brush over the eye. You could try hiding the pin by hitting the h key. Hit the h key again to show them.