Should or shouldn't the guy on page 11 of the latest American Surveyor magazine have both eyes open when operating an instrument?
Hmmmm, don't think that it matters with me, at least. I get the same reading both ways.
I always use both eyes to look at the S6 whilst she's cranking angles- then I use both eyes to look at the screen on the TSC3....:-D
The book "Elementary Surveying" by Breed, Hosmer, & Bone, which I read cover to cover back in '72, clearly stated that both eyes should be open when looking through the scope, as closing one would result in eyestrain. They did recommend figuring out your dominant eye though, and using that one to look through the scope with.
One eye only
I certainly don't hold to keeping both eyes open.
Not sure I ever did, but 7 years ago I had multiple eye operations leaving my right (dominant) somewhat lacking.
I switched to using my left eye looking through the instrument.
Can't say my work suffered in any way.
Suppose the proof is in the eating (seeing) as they say.
I was told eye strain comes from constant peering through the scope with the one eye. Not related to what other eye doing.
I find best is to turn away from instrument and focus on other things.
If using 2 eyes on computer monitor same applies.
If he is taking a reading he should take his hand off the instrument. While he is at it he may as well borrow the digital level from his buddy at the golf course.
Kudos on the clean white shirts all around though.
I use one eye most of the time.
Closing the non-sighting eye reduces the visual acuity in the sighting eye. We used to do a demonstration in hunter ed classes using students. 9 years and every time it proved true...