If you're reclined (on your back) a bamboo chop stick (or light metal tube that's a bit bigger held with the tip a couple of inches above your forehead works. M

If you're reclined (on your back) a bamboo chop stick (or light metal tube that's a bit bigger held with the tip a couple of inches above your forehead works. Make sure your thumb (and no fingers) are below the stick so it will fall.