Visine works by constricting the vessels in your bloody eyes, the same vessels that were opened up by tetrahydrocannabinol’s tendency to relieve pressure in the eyeball. If you use a lot of Visine and you’re not a welder, an Olympic swimmer, or someone else with eyes under constant assault, the actual use of the bottle of Visine you keep in your top desk drawer is more obvious than you think it is. But the active ingredient, tetrahydrozoline, can also cause life threatening symptoms, even in small amounts. This lady tried to poison her roommate with Visine, this guy tried to murder his wife (he eventually tried to hire a hitman when it didn’t take), and this lady tried to kill a cop. So in short, Visine is hard core, like pitbulls and Omar Little. Don’t mess.