Globe front sight

[PWC]

I understand how the eyes automatically try to "center" objects inside a circle.

Now, when using an aperture rear sight, with a globe front; do you focus on the front sight, or the target when trying to center the bull in the globe?

 

[JohnKSa]

Part of the benefit of an aperture sight is that it helps increase the depth of focus of the eye in the same way a pinhole camera works.

You can try a smaller rear aperture (assuming the lighting is sufficient) if everything isn't already in focus. That should sharpen things up and get everything in focus at once.