There is no redness on the skin nor in the eyeball itself. I can't see or feel a bump anywhere in the area (possibly ruling out Chalazion?). My vision is still just fine, but I obviously can't open my eye very wide because of the swelling. The pain is not bad, but it is tender to the touch and if I blink hard. No discharge. I don't think it's allergies, since it's only in one eye and the other eye is perfectly fine.