What about the process of focus? of turning our eyes towards a point of concentration, to observe what falls in our center of vision?  We assume this gives us the clearest image, and often disregard the peripheral information that comes in, as if it is a distraction from our “point”. 

How does our journey into the dark affect the focus of our vision?  As light decreases, the sensing of light by the human eye passes from the cones to the rods.  Remember the cones are “concentrated” at the focal point on the retina responsible for detecting ight in the center of our visual field, and specifically sensing variations of  light wavelengths we perceive as color.  Rods are more concentrated away from that focal point, and do the job of “black/white/gray” light sensing and sorting. 

When we go into the shadows, the “center of the eye becomes blind”, and optimal sight involves not looking at visual targets, to allow the rods to perform their sensing tasks.  Pilots are taught to be aware of the peripheral input, and develop a “sight” that depends on this attention to the bigger picture, and actually disregards the center of the visual field. 

In human psychology, it is well-known that adept survivors use anything accessible as a tool for their success.  These folks sometimes brave challenges so difficult we are amazed they live through them.  Maybe the very human factor responsible for their survival is the ability to see all the different angles of a situation, by paying attention to the light thrown out to the edges, and even disregarding the obvious center of view. 

And, this transition of awareness to include a bigger picture can only occur by a movement into what we consider the dark.