My left eye hurts when i blink. what do you think is wrong?

Many possibilities: Could be something in your eye, an infection, an inflammation, dry eye, scratch on your eye. Try some over-the-counter artificial tears for relief. If the pain does not resolve in a day, see an ophthalmologist.

Need exam: Could be an inturned eyelash, but you should be examined.

Many things: Could be many things! a foreign body embedded under the lid or in the cornea, an in turned eyelash, a corneal or conjuctival abrasion (scratch), a concretion (deposit under the back of the eyelid, a stye, etc.