The fang of a spitting cobra has a discharge orifice at the front rather than the tip, angled forward so that muscular pressure on the venom gland ejects a jet rather than injecting a bolus. The snake can spray from a reared posture over a distance of a couple of metres.
Aiming is active. Filmed sequences show the snake fixating on a face, and during the very short discharge the head rotates so the streams sweep a pattern rather than striking a single point. Studies also indicate the discharge is timed against the target's own movement, which raises the chance that at least one eye is hit.
The target choice makes sense: venom on skin does little, but on the cornea it causes intense pain, inflammation and, without prompt irrigation, lasting damage. Spitting has arisen more than once within the cobras, which is evidence that it is a defence against face-forward threats. Whether large primates specifically drove that evolution is a hypothesis rather than a settled finding.