You Strobe, I Strobe, We All Strobe Together

"I have never seen anything that messes with the eyes like the strobe. It is a fighting tool," says Louis Chiodo in "The Snubby Revolver" by Ed Lovette. "It can help the officer get inside the suspect's OODA (observe, orient, decide, act) loop. If the suspect is at the top of the loop (observe) when the officer uses the strobe and the officer is at 'act,' the strobe can disorient the suspect long enough to buy the officer the extra time he needs to control the situation."

— Reprinted with permission from the author.

At its most basic definition, strobing is using a handheld flashlight with a flashing feature to gain a tactical advantage over a suspect. Strobing disrupts a subject's balance, short-circuits his perception, causes him to look away and induces mental confusion.

Because of its powerful tactical effects, strobing has gained a strong foothold in law enforcement. These new, powerful and efficient flashlights with advanced circuitry (See "Strobing lights" on Page 10.) have even created a unique vocabulary among officers, who are now heard to utter things like, "He strobed," "I strobed" or "He strobed while I moved up."

Louis Chiodo, who as a firearms instructor for Chula Vista, California-based GUNFIGHTERS Ltd. has trained personnel from approximately 95 national and international police agencies, says strobing affects a person's ability; it gives them different perceptions. He emphasizes the greatest benefit a strobing flashlight can provide is its ability to "open up doors." His low-light classes at GUNFIGHTERS Ltd. help participants capitalize on the momentary disorientation strobing provides. During his training sessions, one easily recognizable trend is the close quarters advantage of the strobing light.

Strobing also can be used to prevent the subject from certain areas or routes of escape. Officers who form a perimeter after a pursuit can channel the anticipated route of a suspect to a more desirable one by strobing an area of denial.

Officers can also exploit the momentary short-circuit caused by strobing. For example, when the suspect is frozen momentarily in time, the officer can order him to "slowly point out the location of any other suspects/weapons in the car." This short-circuit, plus verbal stimuli may produce a useful response.

The science of strobing
Strobes have been installed in residential and commercial alarm systems for decades. These systems are known to cause mental confusion and a sense of immediacy, as well as short-circuit the decision-making process. When combined with the piercing sound of an alarm, strobes are effective at removing personnel from an area. The military also has experimented with using strobe lighting "to disorient and confuse personnel" and reduce collateral damage.

But not all of the effects of strobe lighting have been completely explained. It is known that the human brain prefers continuity in order to process information. If the stimuli from different senses seem incongruent, it causes confusion.

Scientists have determined, unlike eyes in animals, the human eye is incapable of detecting motion. Motion is perceived by the human brain and not from sensory input to the eye. Because of this, human perception of color and motion rely on the brain's ability to decipher smooth regular motion. When perception input arrives in segments, the sensory information received by the brain is confused.

Any light source that overloads the photoreceptors in the eye will produce an afterimage, sometimes called persistence of vision. This can occur in two phases: The first phase arises from the immediate discharge of the photoreceptors, the second from a loss of sensitivity. Both produce afterimages. Persistent images alone can short-circuit the brain. Strobing tactical lights work because they do not allow the photoreceptors to reset, which shocks an individual's vision.

Strobing forces the brain's perception input to arrive in segments, albeit regular intervals. Officers can increase the perceptual disparity (and officer safety) by moving while strobing. The afterimages strobing produces further increases perceptual disparity effects.

Certain types of drugs may also amplify the effects of strobing, compounding the effect, though "Law Enforcement Technology" researchers could not find any data supporting this theory. Most officers know certain drugs, especially stimulants, dilate the pupils of the eye, which is evident even in bright sunlight. These dilated pupils also may be less likely (depending on the drug of choice) to rebound quickly enough in response to a bright light.

The Bucha Effect
Another effect of strobing can be The Bucha Effect, which is a phenomenon that occurs when a person experiences dizziness and confusion when exposed to strobe lighting. It is named after Dr. Bucha who identified the effect when asked to investigate a series of unexplained helicopter crashes in the 1950s. After the crash, surviving crew members said they experienced dizziness and disorientation from the strobing affect of rotating helicopter blades.

The Bucha Effect is similar to photosensitive epilepsy, a form of seizures triggered by visual stimuli that occurs in patterns. However, it is not limited to persons with epilepsy. About 3 percent of the general population is susceptible to patterned lights, flashing computer screens and other visual stimuli, such as sunlight through a row of trees viewed from a moving car. The Bucha Effect is not a seizure but has similar symptoms. Like photosensitive epilepsy, its effects are mitigated by distance, relationship of source to the periphery of vision and brightness.

The Bucha Effect may partially explain what happens when a person is strobed. Residual or persistence of vision may be the other part of the equation. Whatever the mental effects, strobing works.

Any limitations to the officer?
However, if strobing affects the subjects, couldn't it affect the officer using the strobes as well?

Because strobing produces a reduced ability for distance estimation, it brings up a training challenge. Is the shooting ability of the strobing officer degraded because of altered perception? Is there a delay or loss of accuracy for the officer who lights his target with the strobing light, then shoots?

"Law Enforcement Technology" researchers recently investigated strobing from the officer's perspective. Our researchers wanted to know if a strobe affects the officer's ability to align sights, maintain a sight select picture and keep a steady shooting platform.

To answer these questions, researchers set up an experiment to determine if the officer's ability to shoot while strobing is affected in comparison to using a steady beam to light a target.

For this experiment, researchers used replicas of duty guns, testing shooting while strobing in ambient light. Replica guns were used so muzzle flash would not be a factor in the test. They shot the first set of targets in visible ambient light, then shot the same targets while employing flashlights with steady beams. Finally, researchers shot the same set of targets using the same shooters and strobing flashlights.

After researchers tallied up the times it took to accurately take in the three different modes, they found the average times of all three events showed little variance. The research suggests that shooting using a strobe is not much different than shooting while employing other lighting sources, provided the officer is the giver, not the recipient.

Chiodo helped researchers put their efforts into perspective. He suggested that trying to demonstrate precision shooting using a strobe may result in answers, but questioned whether researchers were asking the right questions. He noted using shooting methods that rely on fine motor skills rather than fighting methods, which must be effective when the sympathetic nervous system is activated, are a better test of a combat effective product or method.

"When we put two people armed with identical Airsoft products into dark rooms, the person with a strobing light will generally prevail," says Chiodo, who pioneered the use of Airsoft equipment in firearms training programs and instructs many law enforcement professionals in low-light tactics

It appears strobing definitely "opens doors," as Chiodo says. The purpose of strobing is to give an officer control over the target, reducing the ability of targets to aggress the user. This control reduces the potential for harm to the officer and the subject. The strobing tactical light is one of the best modernizations of the officer's toolkit.

Lindsey Bertomen is a retired police officer who teaches Administration of Justice at Hartnell College in Salinas, California. He may be reached at