The Vision's attack was his Optic Beams. In the Comics/Cartoons/Video Games, these can be done from his eyes, or from the Solar Jewel on his head, where he collects ambient solar energy. Shooting from the Jewel is stronger but requires more power. In the movies, he only shoots from the Mind Gem in his head.
This beam is a laser beam. Earlier in the film, when he first shows up to the big Team Cap vs Team Iron Man fight, he burns a line in the ground with it. It's not a concussive wave which would push or break things, it actually burns. When Tony and Rhodes asks Vision to stop Falcon, Vision takes aim as to destroy Falcon's jet pack, forcing Falcon to glide mode. But since he misses his target when Falcon dives, the beam acts like any laser or photon beam, and expands as it gets farther away from its emitter.
Heavy Science From the Physics stack:
Due to Heisenberg uncertainty principle, one can't really make a quantum have zero momentum in any direction. So you can't say that photons go in the same direction - this is just a simplified description of laser operation. In reality, the thinner the beam, the higher the divergence.
Compare e.g. a DPSS laser (e.g. green laser pointer) with a diode laser (e.g. a red laser pointer).
In a DPSS laser the active material will have diameter of order of hundreds of micrometer, and the exiting beam will start from even smaller diameter for various reasons. The divergence is quite small: if you remove the collimating lens, your light image from a green laser pointer will be several centimeters after the light goes several meters.
If you try doing the same with a red laser pointer, you'll see that its light diverges quite a lot: after going several centimeters in direction of propagation, it'll already give image of several centimeters. The reason for this is that active zone of diode laser has diameter of order of several micrometers. This makes output beam quite thin, making Δx small and thus Δp high, and this is what leads to high divergence. Actual angle would depend on which transverse direction you select, because active zone is ∼10× longer in one direction than in another.
Vision was targeting an object at X distance, and adjusting his beam for that. He ends up hitting something at X+n distance away, and the beam was bigger than he wanted at that extra distance. Just like a regular green laser pointer close up, and at airplane distance:
War Machine was disabled, and Rhodes experienced extreme injuries due to the fall. He broke his back, injures at the Lumbar L1-L4, amongst other organ trauma. His paralyzed status was from physical damage, not from any mental effects.