On Tue, 26 Apr 2016 11:49:58 +0100, tony sayer wrote:

In article , NY
scribeth thus
"Mr Macaw" wrote in message news
"The visual field of the human eye spans approximately 120 degrees of
arc.
However, most of that arc is peripheral vision. "

https://en.wikipedia.org/wiki/Vision_span

Wikipedia contradicts itself in another article:

No, the difference is whether you are talking about one or two eyes.

No, with one eye it says 100-110 degrees outwards and 60 degrees towards
the nose. That makes 160-170 degrees.

Anyway, we were discussing sight, not sight with one eye shut. We were
discussing how far round you can see an object when looking straight
ahead.

I presume "when looking straight ahead" means without swivelling your eyes.
Maybe there should be two sets of figures with/without swivelling, because
when you detect something on the periphery, you look towards it (by
swivelling the eyes) and then see a bit further round in that direction.

200 degrees sounds incredibly high, but I've never tested my field of view.
I would have guessed that it would be slightly under 180 degrees - but that
it a guess without any testing. Maybe it *is* a realistic figure...


It is oddly enough a good test to see if your pituitary gland isn't
playing up as this swelling, with a tumour of the same name, can affect
the peripheral vision as it presses on the Optic nerve.

My neighbour had a stroke and got tunnel vision (up to 3 months of it according to the doctor).

Guess who's got one of they;!(

Usual method is to stare at a fixed point in front of you then with your
arms outstretched at the same level as your eye and with your thumb up
wiggle that from side to side and move it around towards the back of
your head it usually is around 108 deg in total the field.

Bring it back and as soon as you notice the movement of your thumb
whilst staring straight ahead that is the angle at that point..

--
Einstein married his cousin, Elsa Lowenthal, after his first marriage failed in 1919.
At the time he stated that he was attracted to Elsa "because she was so well endowed".
He postulated that if you are attracted to women with large breasts, the attraction is even stronger if there is a DNA connection.
This came to be known as.... Einstein's Theory of "Relative Titty."