My eye is irritated whenever I blink, what is going on?

Irritation. You may have something under your eyelid. I recoomend using saline eye wash to try to rinse it out. If that doesnt work try lubricating eye drops. You may have dry eyes or eye allergies. See an eye doctor if these dont work.
Eye irritation. If blinking is causing a foreign body sensation you may have dry eyes, a corneal scratch or a foreign body or misdirected eyelash. You can try artificial tears for a day or two but if no improvement you should see an eyemd.
You need an exam. You may have a condition called giant papillary conjunctivitis which is quite common if you are a contact lens wearer. Also a condition called vernal conjunctivitis can cause similar symptoms. You need to be checked by an eye doctor and insist they evert (flip) your upper eyelids to check for these and other possible conditions.