Long ago I had a dream.
I walked into a room to find my brother on his knees staring into a hatch in the floor.
He would close the hatch for a moment, then impulsively open it again, over and over.
I walked over to see what he was looking at.
When I looked down into the hatch it was a swirling darkness, immediately I could feel the immense drawing power. It was so addictive. Compelling the viewer to look again and again.
It was the dark meditation leading downwards.
Suddenly, I was transported to the top of a mountain.
My old master was in stance with two golden bands on his forearms. He was moving his forearms so as to catch light on the large golden forearm bands. I looked up and saw that he was catching light from presumably the sun and reflecting it off the golden bands onto a large golden disc that sat on a slightly higher portion of the mountain. The golden disc radiated in a very beautiful manner.
This was the light meditation leading upwards.
It was entirely voluntary. Requiring conscious willing participation on behalf of the viewer. No addictive quality whatsoever.