Light against the light: Does the ceiling light in the cabin help from blinding the headlights?
Blinding the driver with headlights of oncoming cars in the dark is an eternal problem. And with the advent of modern halogen lamps with increased luminous efficiency and cheap kits for self-installing xenon, it has become only sharper …
If the rear blinding was partially overcome by the use of electrochromic auto-dimming mirrors (although budget cars usually do not have such a function), then backlight is still dangerous for cars of almost any class and price. For those who often travel at night, the fight against this phenomenon is divided into “passive” methods (special glasses “anti-headlights” and filter screens attached to the visor before the driver’s eyes) and “active” – in the form of background backlight devices, that pre-adapt the eye to the approach of a bright light source outside. We will talk about the latter now! For example, in Soviet times, the FP-03UZ anti-glare flashlight manufactured by the Riga Experimental Plant of Mechanization Tools was a popular automobile gadget.
The device was incredibly primitive in electrical terms – it was a luminaire powered by a cigarette lighter with a 5-watt light bulb and a power button. The luminaire was attached to the windshield over the head of the driver on a suction cup and allegedly reduced by 20-30% the time it took for the eye to adapt to the “light stroke” caused by the oncoming vehicle emerging from the darkness on the night road.
Why is the blue filter used in the antidazzle lamp instead of, say, green or completely unpainted? It is all about the physiological features of human vision: the sensitivity of the photoreceptors of the eyes during dark adaptation is shifted to the blue part of the spectrum.
Many of those who did not bother to read the instructions, believed that the light of the anti-dazzle flashlight should have been sent to the driver’s eyes, but this is a common misconception! In various automotive forums, the old school flashlight OP-03UZ is often commemorated today, but usually in this spirit: “But my father / grandfather in Zhiguli / Moskvich / Volga had such garbage, but after one or two applications, it was thrown to the far corner as useless and even harmful! ” We managed to get a device for retro-test in the “time capsule” state – brand new, in packaging and with paper instructions, which clearly states: “The anti-glare lamp is mounted on the inside of the car’s windshield so that the light beam is directed PARALLEL to the glass and created the backlight for the driver’s eyes ”
Of course, we could not deny ourselves the pleasure of trying the gadget from the past in practice in order to understand – is there any effect from it? We install in accordance with the instructions, parallel to the glass, turn on, having received an intimate pale blue light, and hit the road on unlit roads!
What can I say? Surprisingly, the effect really is! The discrepancy with oncoming cars on unlit night roads occurs with less strain on the driver’s eyes. Not to say that the improvements are radical, but they are clearly visible. Here there is only one nuance … the same effect is provided by the included ceiling lamp of the regular salon lighting!
But why, then, was the “anti-dazzle lamp FP-03UZ” produced, if it could be replaced with a standard backlight? And the reason is simple – on many models of Soviet cars, ceiling ceiling lights were either completely absent (as, say, on classic VAZs), or placed not where needed — not over the driver’s head, but behind it, in the center of the roof (for example, GAZ-21, Moskvichi 402-408, and so on) But on cars like AZLK-2141 or VAZ-2109, the salon plafond stood not far from the rear-view mirror and could well play the role of antidazzle illumination. They “OP-03UZ” was absolutely not needed.
It should also be noted that in the amateur radio literature from the 1970s and until the 1990s, schemes of automatic anti-glare devices were often published, which were the same flashlights over the driver’s head, but with the inclusion of a photocell, which received a signal from oncoming headlights. True, because of the inertia of operation, and also because of the need for constant manual adjustment of sensitivity, such homemade products were not popular.
Today, in the era of cheap LEDs and high-speed microcontrollers, this story has risen from oblivion – for example, a certain German company produces the Anti-Dazzle Lamp AntiBlendLicht – an LED panel mounted on the sun visor and automatically activated by a command of the built-in light sensors. This gadget is worth 100 euros (!) In the version for passenger cars and 200 euros (!!!) in the version for trucks, differing only in 24-volt power …
And finally, it should be noted that the problem of dazzling drivers with headlights infinitely attracts inventors, both serious and insane – something new is regularly being patented on this subject! Of the most curious and partly fantastic, five are not yet implemented.