People occasionally look upward - at a stop light or at a road sign, or occasionally at a startling cloud or sunset, but for the most part we keep our worlds within about 4-5 feet of the ground. Especially if you work at a desk or at a computer. We look downward a lot and this becomes habitual.
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There is a great practice in jo and sword work to help counter this - when working solo kihon or suburi, you want to find a reference point in the distance - upward from the horizon. Trees and the corners of buildings often work nicely for vertical strikes like menuchi and honteuchi. Focus your eyes on these reference points in the distance and pretend that your jo/sword is a giant paintbrush and paint a stripe down the tree or down the distant corner over and over.
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The old dead guys referred to this as enzan no metsuke - gazing at the far-distant mountains, and it is an important practice in creating a good mindset as well as proper posture.
