Safe Speed Forums

On returning from a recent visit to the opticians for the eyesight test having had to wear specs for reading / close work for the last five years or so I got to thinking about the issue of eyesight and driving.

Now I can easily read number plates at about double the distance set out in the Highway Code which is 20.5m or 67 feet in old money so I have never worried unduly about not being able to see when driving

However the optician says that I could now do with glasses for middle distance vision as I am getting more long sighted and may need the glasses for such as sighting middle distance road signs so he is going to make up a pair which will do just that which I should wear as needed. Driving down the motorway long distance vision probably not necessary. In town lots more traffic and direction signs then wear the glasses especially in poor light conditions.

The eyesight standard in the Highway Code is positively primitive. Driving test examiners who ask if you will read the number plate on that car over there are hardly ophthalmic opticians are they? The police who as per rule 81 have the power to require a driver, at any time, to undertake an eyesight test in good daylight. Now is that not a bit daft. I am stopped at night but cannot have my eye sight tested even on the basis of can you read that number plate over there, until good daylight is available.

So how do we ensure that everyone can see to drive safely? Some sort of optical health certificate from an optician? My optician keeps asking if anyone in my family has ever had glaucoma. The existing method of eyesight testing per the Highway Code, does not take any account of eye disease unless you cannot see the number plate at 67feet. How often should we have to certify to the authorities that we can actually see? Is an MOT for drivers now required? Discuss.

I'm more worried about eyesight defects like tunnel vision than actual focus / resolution issues.

I figure I can drive perfectly safely in heavy rain or in fog when no-one could possibly pass the standard eyesight test. That tells me it's far more important that I drive to what I can see, than it is to meet any particular standard.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

I think you're absolutely correct there. I know of someone who is registered blind because of severe tunnel vision but who can pass the standard driving eye test if wearing glasses. The fact that all she could see clearly would be the area immediately around the numberplate she was reading is beside the point.

However many visual defects, including a reduction of field of vision below 120° horizontally and +/- 20° vertically, are a bar to driving. (See the DVLA booklet "At A Glance" Chapter 6 for details) So, the eyesight test that the police can carry out at the roadside or that you're required to undertake as part of your driving test is woefully inadequate.

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Will

I'm convinced that far more KSI accidents are directly caused by uncorrected defective vision than by the breaking of speed limits. Where is the outcry against driving with defective vision? None, of course, as it wouldn't be politically high-profile and profit making.
Then there are the drivers who can see, but who constantly look in the wrong place for hazards and they are in addition to those Paul mentions with 'tunnel vision'.
The A14 near me has a very poor accident record. So, with the shortly-to-go-live SPECS, the new matrix signs are saying "Watch Your Speed" and not, as might be more sensible "Watch where you are going". So, the message is that here is a road with poor safety record, yet we, the highway authorities, want you to watch your speedometers closely at all times to improve road safety. Idiots.
"Get your eyesight checked and look well-ahead" would be a far better message.

There is an test an optician can do called a Visual Fields test http://www.goodhope.org.uk/Departments/eyedept/visualfields.htm that measures the peripheral vision.

According to the current DVLA "At a Glance" medical requirements there is a requirement to meet certain standards if you are subject to certain medical conditions or otherwise stop driving.

Its important for everybody to have regular eye tests by an optician for the sake of their own health.

Just ask your optician to confirm your eyesight is up to the minimum standard for driving.


Then campaign for it to be made compulsory for all drivers at regular intervals.

Many countries actually have that requirement already and those who need glasses to meet the minimum standard have their licence endorsed "only valid if corrective lenses are worn".

Unfortunately the standard eyesight test does not include a 'peripheral vision' test. When I had my very first RAF aircrew medical there was a test in which the examiner moved both hands from behind the head forward and you had to say when you became aware of the movement on both sides. Normally an field of movement perception of around 170 degrees would be normal. Less than this is an indication of 'tunnel vision' which makes spacial awareness a problem. Many drivers have tunnel vision and thus are not able to track the movements of vehicles at the normal limits of peripheral vision. Long distance vision without good angular awareness is not necessarily safe.

No. Not without evidence that it's a genuine cause of crashes (which really doesn't exist).

Just because it sounds as if it should be important doesn't make it so. And even if 'eyesight defects' are eventually identified as a significant crash causation factor, we still need to get really specific about what the true causes are within that set. For example:

- eyeglasses not worn
- night myopia
- tunnel vision / reduced peripheral vision
- colour blindness
- short sighted
- long sighted
- loss of acuity/ resolution
- loss of binocular vision

I've actually put those in my guessed order of importance (most important first, based on guessed frequency of crash causation). And you can bet that regulations will get the importances in the list pretty much completely wrong.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

A bit off topic but my observation is that children have much worse peripheral vision than adults. Or is it that they willfully ignore anything they are not concentrating upon?

Does this make them more prone to road accidents as in the published stats?

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Malcolm W.
The views expressed in this post are personal opinions and do not represent the views of Safespeed.

Paul: I'd be interested in why you feel colour vision is so important. After all, there is no requirement to even notify DVLA about any colour vision defect, even completely monochromatic vision.

IMHO, colour vision should go right at the bottom (or be completely excluded).

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Will

I've just got one anecdote. I used to know a red/green colour blind chap who kept driving through red lights. I can't for the life of me remember his name. He was a frenchman. He was my boss's boss somewhere I worked in the late 1970s.

As I said, I'm only guessing and I'm well aware of the arguments. But I've always worried about that chap...

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

The facts are that approximately one in eight of all UK males (but considerably fewer females) have a colour vision defect (me included). So, restricting driving because of defective colour vision would affect a massive number of drivers, and the high incidence of defective colour vision doesn't correlate to accident statistics.

You don't acquire a colour defect - you're born with it - and so the colours that you see will seem to be normal even if you don't have perfect colour vision. Many people who have a colour defect don't know it because they've never been tested and they've grown up calling the various hues by the same name as everyone else and they've never seen those colours any other way.

Someone with (say) protanomaly or deuteranomaly (reduced red or green sensitivity - collectively called red/green "colour blindness") will still see most shades of red and green and even if they have the "opia" form (e.g. protanopia = complete loss of red vision), they will still see the other colours (amber and green) of traffic lights and know that the stop light is shining because the top ("grey") light is lit. You also quickly pick up the other cues that there are traffic lights (stop lines, arrows painted on the road, crossroads, etc.) and so you see places where traffic lights are likely and then look for the lights themselves.

As I said, approximately 1 in 8 males and some females have defective colour vision and many of these don't know it. So if you don't know for sure, try one of the many online tests - just search the 'net for "ishihara" and you should get a reasonable selection of "standard" tests. However, everyone's colour vision is different and even most who have "normal" colour vision will fail some of the subtler colour-vision tests. For example, this site has tests for protanopia, deuteranopia, tritanopia, and the associated anomalies that aren't "cut and dried", and even if you consider you have "normal" colour vision you might get a few of the plates wrong - but ensure you calibrate your monitor first!

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Will

well these two I qualify for:
- colour blindness
red / green partial... never realy caused a problem

- loss of binocular vision ... never realy bothered me except for at night old landrovers, those with close together head lights apear much further away that they realy were. when pulling out on to a road at night motorcycles need an extra 1/2 second to confirm thier true speed

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Speed limit sign radio interview. TV Snap Unhappy
“It has never been the rule in this country – I hope it never will be - that suspected criminal offences must automatically be the subject of prosecution” He added that there should be a prosecution: “wherever it appears that the offence or the circumstances of its commission is or are of such a character that a prosecution in respect thereof is required in the public interest”
This approach has been endorsed by Attorney General ever since 1951. CPS Code

I agree with Paul. I don't think minor visual defects have much of an effect on driving safety, provided the driver drives to his/her ability, as we should always do anyway.
For years I was shortsighted, and wore glasses for driving. I hated this, especially at might where reflections of the lights of other vehicles could sometimes effectively blind me for several seconds. This was probably more dangerous that driving without glasses at all. After all, I could still SEE everything, it was simply a bit blurred. I suspect the frames of glasses can also restrict peripheral vision.
Nowadays my distance vision is much better, and I don't need glasses to drive, but I am becoming long sighted instead. But more importantly without the glasses I don't suffer anything like so badly from other vehicles headlights at night.

Perhaps in future, they will ban people with long sight from driving on account of being unable to read the speedometer without glasses. The authorities probably consider this more important than distance vision

I have a visual defect and have to wear one pair of glasses for close work and another for distance. They don't overlap and with my distance ones on, objects less than about two feet away are a bit blurred, my dashboard particularly

It came about like this: I began noticing that at night I was having difficulty in judging speed and distance and being more and more dazzled by oncoming vehicles. Not badly but enough to worry me. I was feeling dangerous out at night if truth be told.

I went to see the optician who disgnosed my problem which is basically a binocular problem caused by weak muscles in one eye.

Prescribed corrective glasses have improved my night driving ability enormously and despite an earlier post, I find no problems with reflections or restricted fields of vision.

What bothers me is would everyone do as I did and go to seek help at an early stage as soon as I felt my eyesight was not quite up to the job. I suspect not and as failing eyesight creeps up on you, I'll take a wager that there are a huge number of drivers out there with uncorrected defective vision and posing a severe risk. The cost of glasses may well put some off seeking help.

I would support regular eye tests for all drivers as a mandatory prerequsite to holding and retaining a driving licence.

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Jim

Citroen Xantia: Tears and Joy

That's me finished then

Will have to sell up and get a decent push-bike then...

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Jim

Citroen Xantia: Tears and Joy

I think mandetory eyetests are a great idea actually.

On the subject of glasses causing peripheral vision problems - for the HGV medical there is a limit to the thickness of the lens, after which it is accepted that the lens thickness causes distortion in peripheral vision that is considered too dangerous to pass the medical.

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Science won over religion when they started installing lightning rods on churches.

If he was unable to learn that the top light means stop he probably shouldn't have been driving.

I have been driven by an achromatopsic driver, in other words totally colour blind. His night vision was infinitely superior to mine, it seems that seeing everything as shades of grey has at least one advantage.

Insisting on a proper vision test is essential. at the moment there are a lot of drivers out there who are not aware that their vision is not perfect or who refuse to wear glasses for reasons of vanity.

Poor vision is never going to reduce the risk of accidents, regular testing has health benefits, compulsory wearing of corrective lenses does not limit ones freedom to drive safely - above or below the limit - and there are some people whose vision is so bad they should not be allowed near a car. At the moment we rely on their honesty and/or post accident testing to find out who they are.

Compulsory testing, and the issuing of licences compelling the wearing of corrective lenses where necessary is a very sensible thing to do.

I wear half eyes, sometimes called half moon glasses to corrcet my sight. To see the speedo I look through the lens, to see ahead I look over the top.

I really don't understand the logic of this.

Should all our road safety policies be based on 'what we think sounds reasonable'?

Or should they be rigorously based on allocating scare resources to real crash causes?

'Defective Eyesight' was not recorded once in 147,509 crash reports involving 272,996 vehicles in 2005. (edited to add correction - in the DfT report it shows as '0%' in all categories. It may have been recorded a handful of times.)

Nothing personal, Fisherman, but really, we must go for policies that have a chance of saving lives.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety