An optic that is mounted up higher allows for ones head to be more upright giving superior performance in the following areas:
Better Situational Awareness
Less helmet shift that interferes with vision and sighting
Less neck strain from having the helmet and NVG’s tilted off center
Overall better balance and smother movement

Optics are the primary and in some unit’s the 2nd back up. If the primary is a 1.?-4X of some kind (TR21, Short Dot, NF…) the CQB dot (M68, EoTec, MRD) is the secondary and the Irons are the last resort . If the optic goes down, the operator can still shoot using the window, silhouette of the optic or a top adjustment knob as a reference point to aide in alignment until he can remove the optic and go to a secondary optic before being reduced to the irons.

The advantage of the optic is in reducing the number of things in the sight picture down to 2 ( retical & Target) from 3 ( Rear sight , Front sight & target). The “absolute co witness “ is a step back wards as you now have 4 things in the sight picture (Rear sight , Front sight retical & target).

Out,
2011BLDR