My rifle sights have a simple 1/4 in square notch on the rear and a wide front {blob....about 1/8th in wide. When the front sight is level with the rear when sighting, I'm "on" at up to 50 yards or so. At 100 yards, I put the front sight above the rear sight ie resting on the imaginary line above the notch.
Very fast, and easy to see , since I can concentrate on the target. It doesn't matter if the sights are a bit blurry.