AIMPOINT COA OCCLUSION TRAINER

Why cover the front lens?

Covering the front lens of the red-dot sight forces the shooter to stop treating the optic as a conventional sight that must be visually “looked through.”

With both eyes open, the brain can superimpose the illuminated dot from the covered optic onto the visual scene seen by the other eye. The shooter can therefore still perceive the dot while the front lens itself is physically obstructed.

This is useful because it reinforces several important concepts:

• Binocular vision: the shooter learns to use both eyes rather than depending solely on the eye looking through the optic.
• Target focus: the shooter can maintain visual focus on the target instead of shifting focus to the dot.
• Presentation mechanics: a consistent pistol presentation becomes much more important because the shooter cannot simply hunt for the dot through the window.
• RDS acquisition: it demonstrates that the dot doesn't need to be “found” by looking through the optic; a correct presentation brings the dot into the shooter's visual field.
• Reduced optic dependency: it teaches that the optic is an aiming reference, not a tunnel through which the shooter needs to see.
• Real-world robustness: the exercise helps illustrate what happens when the optic's forward lens is contaminated, partially obstructed, or otherwise degraded.

The key training point

The exercise is particularly valuable because the shooter discovers that the dot can remain usable even when the optic's forward lens is obstructed — provided they maintain binocular vision.