There’s a clear and present danger on the roads today, or rather tonight. It presents itself as a dedicated guardian, a steadfast knight, the silent protector of our bravest men and women. But not unlike the Sirens of Greek mythology who lulled and shipwrecked passing sailors, these beautiful beacons of safety sing a sad song… and it doesn’t end well.
Consider the Bucha Effect; a phenomenon caused by high frequency flashing lights which results in disruption of brain activity. Also known as Flicker Vertigo, it was discovered by Dr. Bucha while investigating several unexplained helicopter crashes in the 1950’s. Pilots were succumbing to it’s effects after glancing up through the main rotor turning in direct sunlight. People who are vulnerable to it experience disorientation, nausea, and possibly seizures (photosensitive epilepsy). It’s like watching a 1997 episode of Pokémon.
Exposure to a high intensity light leaves an imprint called an after image even when the stimulus is removed. It becomes more apparent when your eyes have already adjusted to lower ambient light, such as they would while driving at night. Normally, that effect can be lessened by small eye movements. This is what you do when confronted by an oncoming driver who fails to dim their headlights. You look down and away from the light, blink a few times, mumble something under your breath, and carry on. As your night vision recovers, you are probably darting your eyes around. Nothing drastic, but those eye movements are helpful in eliminating after images.
Tactical response teams have specialized flashlights with strobe functions. They use them when dealing in close proximity to bad guys. Strobe lights do not allow photoreceptors in the eyes to reset. The brain cannot fill in the data between the after images and, with each flash, those imprints are compounded. Disorientation, diminished visual perception, decreased peripheral vision, vertigo, and fear all come into play when an assailant is confronted by a properly used strobing flashlight. It is an effective tool for police officers worldwide. It’s so effective, that it has also been used as a sensory bombardment torture technique.
So why are we using it on innocent drivers?
Accidents happen, preventable though they may be, someone right now is in need of emergency services. And right now on a highway near you there is an ambulance, or a police cruiser, or a fire truck. And while those heroes are hard at work, the lights on their vehicles are in full blaze. At night, when drivers are exposed to these lights, there is no escape. When seen in the distance, they distort depth perception, making it difficult to judge distances and when to slow down. In close proximity, one can’t simply blink away the damage they do. They are a distraction of the worst kind; a persistent visual impairment at a time when acuity is critical. The differential in luminance between the intense lights and what a driver’s eyes have adjusted to results in a glare that is both discomforting and disabling. It’s frightening, to say the least.
The latest generation of LED warning lights being equipped on emergency vehicles is overkill for their intended purpose. They have become too bright, too obnoxious, and far too dangerous. They are even used now on snowplows, tow trucks, and road maintenance vehicles. It has become a selling point for the manufacturers of these lights. Brighter is better. But here, there really is too much of a good thing. Emergency responders are now veiled behind a dazzling curtain of light – what was supposed to protect them, has brought them more harm.