Why do I get the impression that someone (not referring to you Edwin!) doesn't understand what the Ganzfeld Effect is... ?
I've got Ganzfeld Effect goggles that can also provide color-therapy (much better than the super cheap option of putting half a ping-pong ball over each eye). You use them with your eyes open and they can't find anything to focus on so they (your eyes) will actually turn off after a short while and all you see is a light grey. This gives them a nice rest! After a session, when your eyes return to normal, everything is much clearer, brighter and more in focus! Remarkably so! Contrary to popular belief, your eyes don't get the same rest during sleep because they don't know the difference between the waking state and dreaming. They will still follow objects they think they are seeing (hence the term Rapid Eye Movement or REM sleep). I also have a couple of devices you can wear at night that will detect the REM state and can signal you inside your sleep to let you know you are dreaming (these are used to learn to induce lucid dreaming which is beyond awesome!). THESE are the kinds of fun things I worked on a PhD for! ?