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Tuesday, May 2, 2017

dazzling headlights ~ dumb deer ! Older you are, more changes you get !!

The phrase – ‘be like a deer caught in the headlights’ – would mean :  to be so frightened or surprised that one  cannot move or think.  Do you know or remember that till a decade or so ago, it was a rule in India that vehicles should have black colour or sticker pasted in the middle of vehicle headlights so that they do not blindgold the vehicles coming in the opposite lane

No doubt deer look cute, they are perhaps dumb too .. ..  one magazine describes them to be vehicle destroyers. They're quite possibly the stupidest animals on four legs — driving anywhere in rural North America is like playing a particularly furry game of chicken. Deer are erratic, unpredictable, and big enough to cause massive damage to your car if contact occurs. According to the Insurance Institute for Highway Safety (IIHS), deer-related accidents cause an estimated $1.1 billion in vehicle damage every year. Understanding deer behavior is one of the first and best ways to avoid accidents.  Deer are social animals and generally travel in groups – once  one animal crosses a road, the others are likely to follow. They also tend to make split-second decisions regarding movement: !
    
For many of us driving in the night is a problem.  An approaching car round a bend or crests a hill and a dazzling glare fills the windscreen and one would have problems of vision. It is extremely frightening and several seconds may elapse before your night vision recovers — putting your own life and those of other road users in danger. The phenomenon is being blamed on carmakers fitting ever more powerful headlights as a ‘safety’ marketing feature. But research shows that because of the basic mechanics of our eyes, the older you are, the easier it is to be temporarily blinded. 

Sadly, headlight glare is involved in more accidents and deaths, according to statistics.  The danger first arose when soft yellow halogen headlamps (which produce light when a filament is heated) began to be superseded by stronger Xenon or High Intensity Discharge (HID) lights in the early Nineties. These produce a harsh blue light that is typically twice as bright. An even brighter generation of Light Emitting Diode (LED) lights started to appear in 2006. These work by passing an electric current through a capsule of gas or via electromagnetic energy and are fitted to a lot of new cars.  Besides the increasing no. of road accidents, campaigners say glare may cause many more minor accidents, which are often unattended by police and go unrecorded.

Glare can even cause a pain-like reaction, according to Dr Peter Heilig, a professor of ophthalmology at the University of Vienna. ‘Glare sends a warning signal to the brain that says “Stop!” ’ he says. ‘It is comparable to the pain signal you get when you suddenly overstrain a joint.’ In response, you may wince or even inadvertently shut your eyes. Are modern headlights really so much worse? Yes, says Professor Heilig. ‘The stark blue light has much higher energy — ie, it looks much brighter — than halogen bulbs, due to it having a much shorter wavelength.’

Mailonline reports that the effect of the glare of modern lights is greater as we grow older, according to John Marshall, professor of ophthalmology at University College London. The main problem is light scatter. The eye’s lens and cornea are not perfectly clear, so when bright light is shone through them, some gets scattered around the inside of the eye, making images blurred or blank. ‘It is the same effect you get from trying to look at a bright light through a misted-up windscreen,’ says Professor Marshall. ‘The older you are, the more changes you get, even to healthy eyes, such as the lens and cornea becoming less clear, so the more problems you will have seeing clearly.

‘At night your pupil opens wider to let in more light, and when your eye meets a headlamp you get more scatter and can’t see.’ Disability glare, when light is scattered inside the eye, was identified in 1927. That it is exacerbated by modern headlamps was discovered ten years ago in a report by the U.S. National Highway Traffic Safety Administration. This found it can take as long as ten seconds to recover fully. Car-makers have tried fitting HID lamps with beam-focusing lenses and self-levelling systems, which aim to angle beams down to prevent cars blinding oncoming drivers when cresting hills. But Rob Marshall, a technical adviser with the UK road safety organisation GEM Motoring Assist, warns these systems are less than perfect: ‘They take time to react, so an oncoming driver can be blinded temporarily.’ The Society of Motor Manufacturers and Traders maintains there is no evidence that factory fitted high-power lights distract drivers and that lamp-levelling technology ensures they are safe. It adds that they are particularly important on poorly lit roads.

But the Government acknowledges there may be a problem. The Department for Transport says the UK has won agreement for a ‘glare’ group as part of the United Nations expert group on vehicle lighting. In the meantime, Professor Marshall suggests drivers might consider wearing clear glasses — prescription or not — with a UV-absorbent coating, available from High Street opticians.

With regards – S. Sampathkumar

2nd May 2017

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