November 20, 2008
10-43: Be Advised...
with Doug Wyllie, PoliceOne Editor in Chief
Tip: Swing your flashlight
Ever notice that color seems to fade at night? That’s because rods, not cones, are what dominates a person’s night vision and makes it effective.
Rods, located in a ring on the outside edges of the inner eye, are more sensitive to light and movement, whereas cones, located throughout the inner eye but in extraordinary concentration at the center, are for color perception. As a consequence, at night there is literally a “blind spot” in the centermost degree (or two degrees in older eyes) of a person’s field of vision. So, peripheral vision – particularly picking up movement at the periphery – activates the most immediate central nervous system response at night.
Now consider a scenario in which you’re on a darkened street and a car is fast approaching. Because the human eye functions differently at night than in daytime, moving the beam light away from the center of the oncoming driver’s filed of view is very important. Alternating between waving a flashlight’s beam at your feet (illuminating and/or “strobing” your torso and legs in the process), and bringing the beam up directly at the approaching vehicle can substantially increase the effectiveness of your handheld light as a warning beacon.
Be well, do good, go get ‘em.
PoliceOne Senior Editor