"Cross-firing", and the advantages of 2-eyed shooting was recognized > 130 years agoPractical Hints on Shooting: Being a Treatise on the Shot Gun and Its Management; Game, Wildfowl, and Trap Shooting; Together with Notes on Sporting Dogs and Ferrets, and Other Useful Information Relative to Shooting
, K. Paul Trench, 1887https://books.google.com/books?id=xrwUAAAAYAAJ&pg=PA63&lpg
Sportsmen are much indebted to Mr. Gilbert for the many scientific inventions which he has made with regard to firearms, both military and sporting. Among the most remarkable of these are his “Two-eyed Sight” and celebrated “Shooting Corrector.” After several years of continued study Mr. Gilbert first produced the two-eyed sight, which was intended to obviate the difficulty so common with sportsmen who have a powerful left eye, and to enable all to shoot with both eyes open.
What was once thought to be fact regarding dominance however turned out not to be.
It was believed, and is still repeated, that dominance is established at birth and does not switch permanently, nor shift transiently and that is incorrect.
I can shift dominance station to station, and target to target, on the skeet field
Rhodri Woodhouse, “A Changing View of Eye Dominance”, 2009http://orca.cf.ac.uk/55827/1/U584362.pdf
The experiments presented in this body of work have shown that eye dominance is not a static phenomenon, as was believed for centuries, but is adaptable to a variety of viewing situations. Dominance switching tends to favour image size as a cue to switching as a larger visual image contains more data that can be used by the visual system.
This adaptability will likely impact upon several other visual processes, such as directional judgements, and the true extent of dominance switching remains to be discovered with this work providing a solid basis for all future studies.
“Eye Dominance and Shooting” by Michael Yardleyhttp://www.shootinguk.co.uk/answers/eye-dominance-and-your-shooting-13003
Age is also a significant issue when considering eye dominance. This is a most intriguing. Most pre-pubescent boys do not have clear dominance in one eye. Post puberty, most (not all) develop absolute or predominant eye dominance in the eye corresponding to their ‘handedness’. As we enter the summer and autumn of our lives things change too. Typically, somewhere between the ages of 45-60, those men who were clearly dominant in one eye may find the other begins to have a significant pull.
And researchers are leaning more regarding the visual processing
difference of females and why a majority need some form of occlusiveStan: the 30 feet refers to depth perception. Binocular summation is not distance related.