See http://perl.plover.com/yak/presentation/samples/slide023.htm... for an example of this advice being given. (And read the rest of that presentation if you have to give presentations - it is quite good.)
(beware of the wired dumbing down of it though)
Now look back at where you started, a movement that takes tens of milliseconds. Imagine how much blur that creates— that image must be completely useless. You're doing yourself a favor to ignore it.
Edit: Since I mention it, I've wondered before if there'd be any value to training yourself to move your eyes smoothly without following an object. This test suggests probably not; the image just isn't good for anything unless it's correcting for a moving object.
In the eye chapter, there was an interesting side-effect of the saccade movement - the "broken watch". This is when your brain fools you into thinking that the picture you see after a saccade has been the same during the movement itself. When you look at your watch and your timing is just right, you will be left with the impression that the seconds arm stays fixed for longer than it should.
I highly recommend the book - it really demonstrates our inner-machinery.
Wikipedia has a simple test: http://en.wikipedia.org/wiki/Blind_spot_(vision)
The book deduces a set of rules that your brain must follow in order to construct a (mostly) correct interpretation of the limited data that it gets. It does this with a series of experiments that the reader can test. While possibly no longer up to date on the latest research, it's simply a delight to read.
In the book he explains how our brain gets a crappy, distorted image from our eyes, and manages to assemble it using a hierarchy of cells [regions] in the neocortex. It's really interesting, I would recommend getting this book, it's only a couple of hundred pages long, and really opened my eyes (ha!) to how the human brain learns.
In that experiment, they showed that, for some value of n, rod cells consistently activated in response n photons, and did not activate in response to (n-1) photons. Thus, they argue, rods are sensitive to single photons.
In some sense, they're right, in a straw that breaks the camel's back sort of way. However, the common mis-interpretation of these results is that n=1; that is, in utter darkness a rod cell would fire in response to a single photon. But this is not what the experiment showed.
(Note that just because a rod cell activates doesn't mean that the organism would perceive light. In order for a signal to reach the optic nerve, a retinal ganglion cell needs to activate. Ganglion cells only activate in response to the activation of a significant number of photoreceptors. Only in some part of the fovea, where there are no rods, is there a 1:1 mapping of photoreceptor to ganglion cell. In most parts of the retina the ratio is closer to 1 ganglion cell per 100 photoreceptors. Furthermore, even if a ganglion cell activates and a signal reaches the optic nerve, that still doesn't mean that the organism will perceive light. It's likely that further levels of processing may filter out transient activations.)
Now, your perception of the visual world is a lot more dynamic than a simple still shot, which seems to be what this is really saying. No argument there.
But once you get to the retina all bets are off. That's the point of this article.
William Horatio Bates (1860-1931) first published his treatise, The Cure of Imperfect Sight by Treatment Without Glasses (title page), also known as Perfect Sight Without Glasses (cover), in 1920.
This guy has some kind of crazy ideas; but the general thing I learned from him is that the shape of the lens of the eye is a function of three sets of muscles that can be trained/relaxed to help vision come back to 'normal'.
A great read. The HN worthy title would be "hacking your crappy vision"
“Despite continued anecdotal reports of successful results, Bates’ techniques have not been shown to objectively improve eyesight, and his main physiological proposition – that the eyeball changes shape to maintain focus – has consistently been contradicted by observation. In 1952, optometry professor Elwin Marg wrote of Bates, ‘Most of his claims and almost all of his theories have been considered false by practically all visual scientists.’ Marg concluded that the Bates method owed its popularity largely to ‘flashes of clear vision’ experienced by many who followed it. Such occurrences have since been determined to most likely be a contact lens-like effect of moisture on the eye.”
This guy claims to have been clinically blind and recovered using similar techniques
Didn't read your link but could this explain why programmers get poor eyesite as they frequently focus on close objects (monitors) and thus the three sets of muscles become accustom to focusing on close objects?
Too bad for them. Your eyes are more important.
Keratoconus (from Greek: kerato- horn, cornea; and konos cone), is a degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve.
Although my doctor said it was not caused by 10+hrs/day in front of a computer, i suspect otherwise. Its a relatively rare condition, and at my current office there are three of us (out of 25) with the condition.
I would like to know, dear HN readers, do you have this condition?