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This is indeed an interesting question. Why can't the brain develop a reverse blur function? We can do this with algorithms (http://en.wikipedia.org/wiki/Adaptive_optics). There was a fad (I guess) once about correcting your vision with practice (http://en.wikipedia.org/wiki/Bates_method).

I guess this is a limitation of the plasticity of our brains. People who have hearing or vision or other losses as young children adapt faster and better than people who have these losses when older.

It would be interesting to understand if young children with vision deficits can learn to see better with time.

My personal recollection is that I had NO idea things were blurry until my first visit to the optometrist when they put glasses on me. Things were so SHARP!

I think the core of this is that out adaptability depends on sensori-motor loops. We can calibrate our responses for faulty sensors, but we don't correct just for the sake of correctness.




> Why can't the brain develop a reverse blur function? We can do this with algorithms

Adaptive optics requires more than just algorithms -- the algorithms' output are fed into a rapidly moving reflective surface to de-blur the incoming light [1] -- so this is a bad analogy. You might be thinking of some of the deconvolution algorithms [2] that the Hubble Space Telescope used before its "eyeglasses" were installed in 1993 to improve its flawed images.

[1] "Adaptive optics works by measuring the distortions in a wavefront and compensating for them with a device that corrects those errors such as a deformable mirror or a liquid crystal array." https://en.wikipedia.org/wiki/Adaptive_optics

[2] "The error was well characterized and stable, enabling astronomers to optimize the results obtained using sophisticated image processing techniques such as deconvolution." https://en.wikipedia.org/wiki/Hubble_Space_Telescope#Flawed_...


Exerpt from http://www.inference.phy.cam.ac.uk/itprnn/book.pdf (page 564):

"Deconvolution in humans

A huge fraction of our brain is devoted to vision. One of the neglected features of our visual system is that the raw image falling on the retina is severely blurred: while most people can see with a resolution of about 1 arcminute (one sixtieth of a degree) under any daylight conditions, bright or dim, the image on our retina is blurred through a point spread function of width as large as 5 arcminutes (Wald and Grison, 1947; Howarth and Bradley , 1986). It is amazing that we are able to resolve pixels that are twenty-five times smaller in area than the blob produced on our retina by any point source. Isaac Newton was aware of this conundrum. It's hard to make a lens that does not have chromatic aberration, and our cornea and lens, like a lens made of ordinary glass, refract blue light more strongly than red. Typically our eyes focus correctly for the middle of the visible spectrum (green), so if..."

I recommend the read for those interested. There's even an experiment you can do yourself to experience your own eyes limitations!




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