Slate's explainer column answers the burning question: what should I do if my eyeball pops out of its socket?
Get it put back in, and soon. The longer you remain in this rare condition–known as "globe luxation"–the more strain you'll put on the blood vessels and nerves that connect your eye to the rest of your head. Your luxated globes will also be susceptible to corneal abrasions or inflammation, and the feeling of your eyelids clamped down behind them won't be pleasant.
You should be able to get your eye back in place without serious, long-term damage. (If the ocular muscles tear or if the optic nerve is severed, your outlook won't be as clear.) The treatment for globe luxation is pretty simple: Doctors apply some topical painkillers, hold back your lashes, and poke your eyeball into its socket by pressing on the white part with gloved fingers. (In some cases, they'll use a simple tool like a bent paperclip to shoehorn it back into place.) You might get antibiotics, lubricating drops, or steroids to follow up for a few days while your vision returns to normal. If your doctors can't pop your eye back in–because you've got too much swelling in the socket, for example–they'll give you an eye shield and consider a more invasive procedure.
(via Making Light)