Vision Science and Business (Optometry)

The men in the laboratory... cannot be said to observe the actual objects of their curiosity at all. ...The sense data on which the propositions of modern science rest are, for the most part, little photographic spots and blurs, or inky curved lines on paper. ... What is directly observable is only a sign of the "physical fact"; it requires interpretation to yield scientific propositions.

Not so many years ago this was a mistake that brain scientists actually made: they succumbed all too often to the temptation to treat vision as if it were television — as if it were simply a matter of getting "the picture" from the eyes to the screen somewhere in the middle where it could be handsomely reproduced so that the phenomena of appreciation and analysis could then get underway. Today we realize that the analysis — the whatever you want to call it that composes, in the end, all the visual understanding — begins right away, on the retina; if you postpone consideration of it, you misdescribe how vision works.

For sight is woman-like and shuns the old.
(Ah! he can see enough, when years are told,
Who backwards looks).