By the inner corner of my left eye, i can feel a tiny ball inside my eyelid that hurts when i touch it. when i blink, it slightly hurts. what is it?

Sty: When not inflamed a "chalazion". When inflamed a "stye". Underlying problem due to an eyelash duct becoming obstructed. A stye might need warm water washcloth soaks, and visit to an eye doctor for topical and systemic antibiotics, and for surgical chalazion excision. I hope an ophthalmologist jumps in here, because this is not a problem i commonly encounter.

Stye: Most likely this is a stye. Treat it by using a hot wet washclothe to the eyelid four times per day. If it does not resolve in a week, see an ophthalmologist.

Heat application: Your trying to liquify fluid in "sty" so it drains. Heat 10 min. Each time. Washcloth gets cold quickly and water runs down your face. Other tricks: heat back of a spoon in warm/hot water and apply the spoon to the sty - repeat when spoon cools. Buy small new potatoes - microwave one. Apply to lid. Not messy, stays warm longer. Dont burn yourself. Also, antibiotic drops/pills if inflamed.