How do we see things upright ?

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dipdude

Forerunner
Source : Physlink

How do we see things upright if the image formed on the retina in our eye is an inverted one?

Answer

It is true that the images formed on your retina are upside-down. It is also true that most people have two eyes, and therefore two retinas. Why, then, don't you see two distinct images? For the same reason that you don't see everything upside-down. One of our most remarkable tools - the brain - is hard at work for us at this task.

Processing visual information is a complex task - it takes up a relatively large portion of the brain compared to other senses. This is because your brain performs several tasks to make images 'easier' to see. One, of course, is combining the two images, which is helped by the corpus callosum, the tiny part of your brain which joins the two big hemispheres. The other part is handled in the optic part of your brain itself, and part of its job is to make images right-side-up. It does this because your brain is so USED to seeing things upside-down that it eventually adjusts to it. After all, it's a lot easier to flip the image over than it is to try and coordinate your hands and legs with an upside-down world! As a result, though, it is believed that for the first few days, babies see everything upside-down. This is because they have not become used to vision.

Your brain CAN be retrained though. In one psychological study, participants were asked to wear inverting lenses - lenses that invert the image BEFORE they get to your eye, so that when your eye inverts it, it's right-side-up. At first, everything appeared upside-down to the participants. But, after a few days, people began to report that everything appeared right-side-up! As a second part of the study, the people were asked to take the glasses off. Because they were now used to the lenses, their NORMAL vision appeared upside-down!! Within a day, though, their vision returned to normal. The reason you don't see everything upside-down, then, is simply because it's easier to think about right-side-up!
 
well its a right answer in a sense but its way short of complicated things involved there in visual areas of our brain.

the process of identifying the special senses is way complicated that even biggest and fastest supercomputers on earth may be put to shame.

to put it in simple words here is what is visual pathways....

Introduction
Thus far all the visual processing, anatomy and physiology we have learnt has been concentrated in the eye. The vast majority of nerve cells associated with vision, specialised physiological processes and visual processing that we perform for seeing occur in the brain. 127 million photoreceptors produce signals that are carried by 1 million nerve fibres to ultimately reach the 100 million nerve cells of the primary visual cortex. Beyond this area hundreds of millions of further nerve cells are waiting to perform more specialised processing on the visual information although this subject will have to wait until the second year course. The organisation of the retinal nerve fibres as they make their way to the primary visual cortex, how the brain solves the problem of squeezing the 50 gallon drum into the pint pot, tells us much about how our visual system may work. Before we can do that however we have to be sure that we understand the relationship between retinal areas and areas in the visual field.

Summary
The visual pathway describes the route by which nerve impulses travel from the retina to the primary visual cortex. At each stage of the visual pathway the nerve fibres are organised in a retinotopic fashion although this map changes continuously as the pathway is traversed. The optic chiasm is the main interchange in this pathway and allows the information from the separate eyes to be organised so that object information from the eyes is kept together. The lateral geniculate nucleus is the second synapse in the visual pathway (the first was between the bipolar cell and the retinal ganglion cell). The optic radiations are the third neurone in the visual pathway and relay the visual information to the primary visual cortex. By the time visual information reaches the primary visual cortex the representation of the macula area of the retina has expanded enormously.

the source : the human visual pathway

this article is meant for optometrists who check the visual acuity of human eyes so it is as simple as it gets.

for us it is still more deeper study but to enlighten more the members of TE this is enough i think.:clap:
 
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