Unlike a digital camera that captures a fixed number of frames per second the eye is composed of millions of light receptive neurons (about 120 million rods and 7 million cones). If we estimate that each has an independent refractory period of 16-20 msec then by my calculations we might estimate the overall frequency of information sampling to be roughly 7 GHz (that is 127m / 18 msec). Now... this number isn't actually all that meaningful because refractory period probably has some spatial correlations, and because a completely new image isn't formed at that rate...still it is quite a high number.
For the purposes of simplifying the discussion, I'll just go along and pretend that the entire image is sampled at some fixed frequency "f" samples/sec. If the width of your visual field is "w" meters then your claim (written mathematically) is that an object having an apparent velocity greater than "w/f" meters/sec is invisible. It is not true that this condition means the object is invisible. It merely restricts the number of sampled images of the object to 1, assuming a fixed eye position -- in other words, no matter how fast it's moving, it can never be moving so fast that you don't get at least one image of it.
In reality, a fixed eye position is also unreasonable...because the eye is continuously making saccades toward "interesting" features such as moving objects. Even when fixating at a stationary target the eye continuously and unconsciously makes micro saccades that allow it to do super-resolution (the same kind of super-resolution that allows, for example, the resolution of a satellite image to be increased...or efficient coding for streaming video).
The truth is, fundamentally, I do agree with you...it's possible that an object be moving so fast that you don't perceive it, or what you do perceive is filtered out by your brain as being noise. But this doesn't mean that you can't get a glimpse or a bullet or a plane or whatever, which I think is what you were trying to argue...ah, maybe I don't know what your actual point was at all...