Dean37 wrote:
As I said, what works is what works. For myself, when I try to keep both eyes open the eyes compete for use as my eyes are essentially co-dominant , and the "unused eye" interferes by taking over. I cannot see through the viewfinder, because the "unused eye" takes charge, or when shooting I can't see the sights because the "unused eye" takes over.
Everybody is different, and while the ideal is to keep both eyes open, that doesn't work for everyone.
I experience something similar.
And for camera use, I would have to try again leaving both eyes open, but as far as I remember the "unused" eye when open sees part of the camera very near and therefore has no good vision