Which eye? Which sight?
Shooting aperture (or telescopic), the gun hardly ever experiences any real problems out of using the off eye PROVIDED corrected acuity in that eye is not materially less than the dominant.
Shooting any sort of sight that introduces resolution of presbyopic problem, though, almost always demands sighting with the dominant eye for good result. Examples are open sights or the ring sight affairs that seem to be a fad. Wingshooting or shooting by point method without attention to sights is another.
When the gun, for good reason or bad, elects sighting with the off eye, he is served best by interrupting the acuity of the other eye sufficently to allow the off eye to dominate in the sighting field. The most effective way the gun or the instructor has of accomplishing this is to put a patch of transparent tape, say .75x.75cm in the upper inside corner of the lens on the eye not being used as the sighting eye. In a pinch, or in the field, simply smudging the same area with a bit of the skin oil off ones nose works quite well. This isn't a bad practice even when the dominant eye is the sighting eye.
This practice of "eyes open always" has a number of very practical functions, most of which are simply taken for granted in target and simulation conditions. However, when the gun is confronted in a variety of adversarial circumstances, the reward of having constant, immediate depth perception, the ability to recognize within a greater periphery, and the ability to not "fatigue out" when confronted with a target demanding a long hold is often that of being the one who walks away from the confrontation.
Hold fast, regard the wind, the light, and the other fellow, and wake up the next day. That's all there is to it.
naco
