My right eyelid is swollen. it hurts and very tender to the touch. it's covering most of my eye and hence clouding my vision. what can i do to reduce the swelling?

Basics: Without knowing what went on before this started (exposures to dust/irritants/working with metal sparks/insect bite) it may be best to have the eye looked at. A comfort measure in the interim would include application of mild moist heat. That improves blood flow & natural healing. However, if there is a possibility of a retained foreign object or scratch of the cornea, it should be seen.