Problem A gust blows abrasive specks of dirt and grit into your eye.
Treatment Resist the urge to rub the eye–you could scratch the cornea. Immediately try to flush the grit out by applying a few drops of artificial tears (such as Bausch & Lomb lubricant eye drops; stash a small bottle in your first-aid kit). No luck? Have a friend gently pull your eyelids out to check for particles; to see the upper lid, fold it over a small (clean!) stick or cotton swab. Carefully remove any specks with a moistened piece of gauze–if it doesn’t come away easily, or if the speck is stuck to the eyeball itself, lie on your back and have your buddy gently pour potable water into your open eye. Assess after a few minutes and repeat until vision returns to normal. Still feel irritated? The eye could be scratched.
Prevention Wear sunglasses, of course, especially in arid or sandy areas.