I don't have the numbers in front of me, but visual field testing is a pretty standard neurologic exam. The bedside test is you have the patient stare straight ahead, then have them identify motion in the periphery. This is used diagnostically for visual field defects. There are more formal "perimetry" testing procedures that include brainstem evoked potentials.

The thing is, this is not really analagous to the field of view of a camera lens. One reason was mentioned, that being rapid saccades or eye movements that dart around to take stuff in, also (as mentioned) getting around issues of DOF.

The other reason is that the field of view covered by our fovea, which is the area of high visual acuity, is extremely small compared with the field of view of our entire retina. In other words, we have a very small field of view that is sharp, but a much larger field of view that is much lower acuity.

This is not a DOF issue, not an optical phenomenon -- it's a neurologic issue in that our retinas, our optic nerves, and everything all the way back to our occipital cortex concentrates attention and resolution on a small area.

Birds of prey have tiny tiny fields of view, but extremely dense photoreceptors -- thus they have incredible acuity, and can resolve things a mile or two away, or see a mouse on the ground as they're darting around a hundred feet in the air.

Edit -- Agx beat me to it.