An experiential horizon structures one’s gaze into the world. Jodi Dean expressed this well in a talk on the Communist Horizon, which she asserts is the political horizon of our age.
The term “horizon” marks a division.
Understood spatially, the horizon is the line dividing the visible, separating earth from sky. Understood temporally, the horizon converges with loss in a metaphor for privation and depletion. The “lost horizon” suggests abandoned projects, prior hopes that have now passed away. Astrophysics offers a thrilling, even uncanny, horizon: the “event horizon” surrounding a black hole. The event horizon is the boundary beyond which events cannot escape. Although “event horizon” denotes the curvature in space/time effected by a singularity, it’s not much different from the spatial horizon. Both evoke a fundamental division, that we experience as impossible to reach, and that we can neither escape nor cross.
I use “horizon” not to recall a forgotten future but to designate a dimension of experience that we can never lose, even if, lost in a fog or focused on our feet, we fail to see it.
The horizon is Real in the sense of impossible—we can never reach it—and in the sense of actual. The horizon shapes our setting. We can lose our bearings, but the horizon is a necessary dimension of our actuality. Whether the effect of a singularity or the meeting of earth and sky, the horizon is the fundamental division establishing where we are.
The Communist Horizon by Jodi Dean
As much as anyting, the horizon is a boundry, but like all boundaries, it seems definite but turns out to be queer.
Standing on a shore perhaps, another shoreline about 2.9 miles across a lake exactly defines the horizon. Boarding a suitable vessel, we set off and land on that beach, only to turn around and see the shore from which we left a short while ago defining exactly the horizon.
Whatever beach we see in the distance is the technological horizon. Both beaches, the intervening water, sky, the boat and we, with our vivid perceptions, are all the cyborg terrain.
I take this phrase from the US military’s Human Terrain System which sets out to describe “the human population in the operational environment”. The Technological Horizon creates the cyborg, not technological artifacts. That is to say that Heidegger’s technological understanding of Being, the Enframing of the counted and measured components of the world  is also the Technological Horizon.
It is the Technological Horizon, not the cell phones, tablets etc, that converts the Human to the Cyborg.
It is the Technological Horizon that converts the military operational Human Terrain System to the planetary Cyborg Terrain System.
It is the Technological Horizon that evokes in Cyborgs Dean’s sense of loss of “the forgotten future” .
A horizon perhaps is not so much a division as an expression of the relationship among perceiver, figure and ground. We can never reach the horizon but at the same time the horizon is where we live. A version perhaps of Heidegger’s “splendor of radiant appearing.”
 The Question Concerning Technology, Heiddeger,