Strobe light is intermittent or flashing light. The effect takes place in the human eye where the image seen during the last flash of light is retained by the retina long enough so that the ensuing image seems superimposed on the first. Early inventors fascinated with the idea of creating moving images discovered that by creating a series of drawings on the pages of little books, called flip books, they could suggest motion to the viewer. These were made literally by hand drawing little figures or images at different stages of movement. A child or horse or dog could run through a series of fifty or so pages once those pages were “flipped” in front of the viewer whose eyes registered each drawing individually but whose mind filled in all the tiny blank spaces and interpreted the images as almost realistic motion.
The earliest efforts at motion picture film were constructed in the same way. A series of images imposed on transparent film by still photography could be pulled through a primitive projector, projected on a screen, and seen as motion. Motion picture photography progressed through dozens of stages very quickly as both inventors and investors capitalized on the human eye’s ability to retain an image through the flickering effect of light. Early movies were called “flickers” for good reason.
Strobe effect is used for various reasons in modern contexts for entertainment, for industrial applications, for research and more. In entertainment, the effects of strobe lighting are used in clubs, shows, films and other entertainment venues for the excitement created by flickering images. In industry, strobe lighted research into the motion of engines and other mechanisms offers the ability to stop, start, reverse, slow, and speed up the images for technical examination. Strobe effect is used in the same way for medical research to examine the function of the body’s organs.
Strobe effect has inadvertent results also on the orientation of some people to their environment. First noted among epileptic patients, extreme confusion, loss of balance, and disorientation may result from exposure to strobe lightning. More and more club goers and rock music concert audience members report nausea, loss of balance, and fear resulting from extended exposure to certain rates of strobe lighting. Natural exposure to the strobe effect can result from driving or bicycling past a stand of bare trees during a sunny winter day which often results in a sustained flicker on one or more sides of the face. Helicopter pilots and crew can be susceptible to the strobe effect created by the motion of the rotors.
Awareness of strobe effect can be helpful for anyone who may be exposed to sustained periods of flickering light. Like any natural condition to which one may be exposed, it is good to understand that a slight confusion or disorientation might result from certain driving or flying conditions. On a more serious level, a concert or club where strobe lighting may be used over a period of time could produce illness in some attendees. While serious effects of strobe light are caused by a combination of brightness and frequency which would be difficult to determine without extensive testing, anyone attending such an event or exposed to flickering light might easily monitor his own response and remove himself from the influence quickly if necessary.