Primal survival skills would require noting the acoustics of the landscape to avoid falling off cliffs, as would be necessary to find shelter. The presence of your enemies would be a bit enigmatic as would be your presence to them; After all, it would be difficult to judge each others size or form.
A sightless world's functional design may be more rounded to achieve an analogous touch-friendly guide through public and domestic spaces; An abrupt and acute angle here or there to represent landmarks along the way.
Most curious of all, our attention to the heavens would not stop short of building great spiraling ramps which lead us further and further and further upwards; century after century. All the while our explorers' arms would be stretched upwards with the hopes of making the headlines for being 'THE ONE WHO TOUCHED THE CEILING"
We would still perceive and even dream these perceptions, but we would unknowingly be missing a piece to the puzzle. As far as (the seeing) you and I are concerned, that's a pretty big piece to have missing. But what is to say that, with all five of our natural senses in tact, we aren't missing that sixth or seventh sense that would allow us to better avoid an accident, or look light years across the galaxy so as to realize the attic beyond the ceiling. As humans we possess basic rules of understanding which are directly connected to our senses, including sight, and to our brains interpretation of those senses. It's not only a limited means of understanding but also reasonably very abstract and misguided. Or as one might say, 'it's like the blind leading the blind.'
