Welcome to Part II of our series on the use of light. In Part I, we discussed the intensity of light, its impact on the human eye, several types of lights, and the characteristics of flashlights. In this session, we will discuss how light acts to inhibit or enhance our senses.

As you may know, even in low light, your eyes will adjust, giving you a rudimentary idea of your surroundings. In a world that is increasingly urban and increasingly well lit, we have a concept that is relatively new to the human experience – an environmental light gradient. This gradient is what creates visual disruptions, as we discussed in Part I, by forcing the eye to transfer rhodopsin in the rods of the eyes (which detect the intensity of light in low light conditions) into subordinate molecules, opsin and retinol, in the cones of the eyes, which allows us to perceive color, detail, and depth.

With that in mind, let’s look at some principles in use of light and their effect on humans.