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Polaroids in head lights

  1. Aug 9, 2012 #1
    I have studied,as one of the uses of polaroids is, that it can be fitted in the head lights of cars and other vehicles to eliminate the glare. This will certainly act as a boon to the motorists and result in considerable reduction of road accidents during the night time.

    I have also learnt that Edwin Land had pioneered in this field as early as 1930's and took sincere efforts to design such polaroid sheets through his company the Polaroid corporation and tried to obtain patent for promoting it for commercial use, but only unsuccessfully.

    Now with the tremendous advancement in technology, are the modern cars coming to the market fitted with any such anti glare headlights? Has any country such as US or UK made it mandatory for fitting such glasses to the headlights of automobiles to avoid accidents?

    In India,whenever I ride on my bike during night hours, I used to think of such scenario, facing the annoying glare of headlights of the vehicles coming from the opposite direction, causing potential risk to the drivers.
  2. jcsd
  3. Aug 11, 2012 #2


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    The filters required don't let much light through. So it's not just the headlights that are dimmed.
  4. Aug 11, 2012 #3


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    In principle, the idea seems very attractive but there are a number of practical difficulties.

    This system would reduce effective illumination by half, even with perfect polarisers. It wouldn't be as useful in rainy conditions with a wet windscreen because of the de-polarisation.
    I have a feeling that a full beam in the eyes when the polariser system wasn't actually working fully could be worse than what you get nowadays with properly dipped headlights.
  5. Aug 11, 2012 #4


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    Not only would you have to fit the polarising filters to the headlights, you'd have to fit them to windscreens too, or else make everyone wear sunglasses.

    I'm not sure, but it might also make retro-reflectors not work properly?
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