this is what I got from Leupold:
To focus the reticle (crosshair), you will need to turn the ocular housing (eyepiece) all the way out. There is a stop in the system, so the eyepiece will not come off. Then, while looking at a blank white wall or other light colored surface, glance through the scope. The reticle should appear fuzzy. While looking away from the scope to allow your eyes to return to normal/relaxed vision, rotate the ocular housing clockwise a couple of rotations. Once your eyes have had a few moments to adjust to normal, quickly glance through the scope again. Repeat this process until; upon first glancing through the scope, the reticle appears clear and crisp against the blank background. It is important to make sure the background is blank, and that you look away, only glancing quickly through the scope. This eliminates the eye's natural ability to force things into focus. Once the reticle is focused, lock the lock-ring into place.
I hope this helps.