Well, fwiw, I should note that on no videos or classes have I seen do VV or MR tilt their head back (which would break form, a fundemental nono).
But let's apply some analytical thinking. How do you look over someone's head without movnig your head and breaking your form? Rolling your eyes.
Rolling your eyes up slightly won't seriously effect your range of vision , but most or at least more of the image of your assailant from 6 feet away (for lack of a better standard, I'm using the distance they used to start us off from in tournaments from back in the day as a standard) will fall into the peripheral zone, outside the foeva centralis. As an experiment, I just walked 6 feet away from the corner of a wall of my office (not too many people in right now). I chucked a pen at the floor while directing my gaze a few degrees up from the horizantal, above my height. Without focusing on the pen, I had no trouble seeing it as it skittered across the floor past the corner.
Up close of course, the whole thing changes.
If you take it that most fights start at punching range, you want to get the upper body under the foeva, so you roll the eyes slightly then, too.
The science is there, and I aim to try this out tonight. Fact is, it is rarely if ever mentioned in class, but I do remember, now that I think of it, noticing an odd upward kant to the eye's of VV, MR, and James from Latvia from time to time. I think, though, that this is really applicable only in certain situations, like a kumite/sparring/squareoff situation. 90% of the close work we do is directed by feel, not vision, at least for me, and if somone surprises you, you have no time to adjust your eyes. On the other hand, as an excercise, rolling your eyes would get you better at recognizing the things you see outside of the foeva centralis, which could give you a better early warning systemm for the hook you weren't looking at, etc. etc..
But let's apply some analytical thinking. How do you look over someone's head without movnig your head and breaking your form? Rolling your eyes.
Rolling your eyes up slightly won't seriously effect your range of vision , but most or at least more of the image of your assailant from 6 feet away (for lack of a better standard, I'm using the distance they used to start us off from in tournaments from back in the day as a standard) will fall into the peripheral zone, outside the foeva centralis. As an experiment, I just walked 6 feet away from the corner of a wall of my office (not too many people in right now). I chucked a pen at the floor while directing my gaze a few degrees up from the horizantal, above my height. Without focusing on the pen, I had no trouble seeing it as it skittered across the floor past the corner.
Up close of course, the whole thing changes.
If you take it that most fights start at punching range, you want to get the upper body under the foeva, so you roll the eyes slightly then, too.
The science is there, and I aim to try this out tonight. Fact is, it is rarely if ever mentioned in class, but I do remember, now that I think of it, noticing an odd upward kant to the eye's of VV, MR, and James from Latvia from time to time. I think, though, that this is really applicable only in certain situations, like a kumite/sparring/squareoff situation. 90% of the close work we do is directed by feel, not vision, at least for me, and if somone surprises you, you have no time to adjust your eyes. On the other hand, as an excercise, rolling your eyes would get you better at recognizing the things you see outside of the foeva centralis, which could give you a better early warning systemm for the hook you weren't looking at, etc. etc..
I hope to have more Systema training under my belt by then, although it's been a little difficult to get to lately (I commute 1 hour each way once to twice a week to train) as my job requires long unexpected hours. 
