Colour Vision and Visual Field in the Lorry Eye Test

Colour vision and visual field in the lorry eye test are the two parts of the examination that most car drivers never have to think about in detail, yet for lorry and bus drivers they can decide whether a licence is granted at all. When you apply for a class C, CE, D or DE licence in Germany, your eyes are not only tested for how sharply you can see. They are also tested for how accurately you can tell colours apart, and for how wide your field of view is, because a professional driver spends long hours on the road, in a large vehicle, with far more to watch than a car driver. This guide explains what those two tests involve, what standards apply, what happens if you do not pass, and how to prepare so that you are not caught out on the day.

Many applicants arrive at the eye test thinking only about visual acuity, the familiar chart of letters that gets smaller line by line. That is understandable, because visual acuity is the headline number on most certificates, and it is the test most people remember from their car licence. For a lorry licence, however, visual acuity is only the beginning. The German rules for professional drivers, set out in the driving licence regulations and in the medical annex that covers fitness to drive, require a fuller assessment, and colour vision and visual field are a central part of it. The reason is practical and safety-related: a lorry driver must be able to read traffic lights, road signs, and signals quickly and reliably, and must be able to see vehicles, cyclists and pedestrians approaching from the side, even in poor light or in busy traffic.

Why lorry drivers face stricter eye tests

Lorry and bus drivers are in a different group from car and motorcycle drivers under the German rules. Car drivers are in group 1, while lorry and bus drivers are in group 2, and group 2 has higher medical standards across the board. That distinction is not arbitrary. A lorry is heavier, longer, and harder to stop than a car, and a bus carries dozens of passengers whose safety depends on the driver. A small mistake in judging a colour, or a blind spot at the edge of the visual field, can have more serious consequences in a lorry than it would in a car. The eye test for group 2 is therefore designed to be more thorough, and it is usually carried out by an ophthalmologist, rather than by an optician alone, because the ophthalmologist can assess the full range of visual functions.

The stricter standard also reflects the working conditions of a professional driver. A lorry driver may drive for many hours a day, at night, in rain, and in heavy traffic, and the eyes are under constant strain. Good colour vision and a wide visual field are not just a one-off test result; they are tools the driver will use every day, for years. That is why the licensing authority wants a detailed report, not just a short certificate, and why the report may need to be renewed when the licence is renewed, usually every five years. If you are planning a career as a professional driver, it is worth understanding these requirements early, so that you can check your eyesight before you invest time and money in training.

Colour vision: what is tested and how

Colour vision is tested with a series of coloured plates, known as Ishihara plates, each of which contains a number or a pattern made up of dots in different colours. If you have normal colour vision, the number is easy to see. If you have a red-green colour vision deficiency, which is the most common form, some of the numbers will be hard or impossible to make out, or you may see a different number from the one a person with normal colour vision sees. The test is quick, it is not painful, and it does not require any preparation. You simply look at each plate in turn, in good light, and say what you see, or say that you cannot see a number at all.

For a car licence, a colour vision deficiency does not normally prevent you from driving, because traffic lights are also distinguished by their position, and most road signs use shapes as well as colours. For a lorry or bus licence, the rules are stricter, because a professional driver is expected to be able to distinguish colours reliably in a wider range of situations, including signal lights, warning signs, and the colours of other vehicles and road markings. A significant colour vision deficiency can therefore mean that you need a further assessment, and in some cases it can mean that a group 2 licence is not granted. That does not happen automatically, however. The ophthalmologist will assess the degree of the deficiency, consider whether it can be compensated for in practice, and make a recommendation to the licensing authority, which makes the final decision.

Visual field: what is tested and how

The visual field is the total area you can see when you look straight ahead, without moving your eyes. It includes what is directly in front of you, and what is to the left, right, above and below, at the edges of your vision. In the lorry eye test, the visual field is checked because a driver must be able to spot a cyclist coming up on the side, a pedestrian stepping off a pavement, or another vehicle in the next lane, without having to turn their head for every small movement. The test is usually done with a machine called a perimeter, which flashes small lights at different points in your field of view while you look at a fixed point in the centre. You press a button, or say yes, each time you see a light, and the machine builds up a map of what you can and cannot see.

A simpler version of the test, sometimes used at the optician, is the confrontation test, in which the tester moves a finger or a small object in from the side of your vision while you look straight ahead. That version gives a rough idea of whether your field is normal, but for a group 2 licence the ophthalmologist will normally use the more precise perimeter test, and will record the results in degrees, so that the licensing authority can compare them with the legal minimum. For professional drivers, the horizontal field should normally be at least 120 degrees, with a reasonable field in both eyes, and the central field should be clear and without major gaps. The exact limits are set out in the medical annex to the driving licence regulations, and the ophthalmologist will know them.

The standards for classes C, CE, D and DE

For lorry and bus classes, the visual acuity standard is higher than for cars. As a rule, the binocular visual acuity should be at least 0.8, with at least 0.5 in the weaker eye when correction is used, although the exact figures depend on the class and on the individual report. That is in addition to the colour vision and visual field requirements, and in addition to a general check that the eyes are healthy. If you wear glasses or contact lenses, you will be tested with them on, and the licence will note that you need them, just as it does for car drivers. If your visual acuity is borderline, the ophthalmologist may try a different prescription, or suggest that you see an optician for a new pair of glasses before the test is repeated.

It is worth reading the detailed guide to the lorry eye test and our article on the eye test for professional drivers before you book, so that you know which documents and which examinations are required in your case. Some applicants need only the ophthalmologist report, while others also need a general medical examination, and the timing of the two can be coordinated so that you do not have to make two separate trips. If you already hold a class B licence, the eye test for class C is a separate test, and passing the car test does not automatically mean you will pass the lorry test, because the standards are different and the examination is more detailed.

What happens if you fail one part of the test

Failing the colour vision test or the visual field test does not automatically mean the end of your plans to become a lorry driver, but it does mean that your application will be looked at more closely. The ophthalmologist will usually repeat the test, check whether the result was affected by tiredness, poor light, or a problem with your glasses, and, if necessary, carry out further examinations. For colour vision, a further test with a different method, such as a lantern test, may be used to see how well you can distinguish signal colours in practice. For visual field, a repeat perimeter test on another day can show whether the first result was a one-off, or whether there is a consistent gap in your field of view.

If a colour vision deficiency or a visual field defect is confirmed, the licensing authority will decide whether it is compatible with safe driving in a lorry or bus. In some cases a licence is granted with conditions, such as a requirement to wear glasses, or a limit to daytime driving, or a requirement for regular re-examination. In other cases the authority may decide that a group 2 licence cannot be granted, and it may suggest that you consider a group 1 licence instead, which has lower requirements. That decision is made on the basis of the medical report, and it can be appealed if you believe the assessment was wrong. If you think there has been a mistake, ask for a second opinion from another ophthalmologist, and keep a record of all of your test results.

How to prepare for the test

Preparation for the lorry eye test is mostly about being in good shape on the day, rather than about studying or practising. Get a good night sleep before the test, so that your eyes are rested and you are not squinting through tiredness. If you wear glasses or contact lenses, make sure your prescription is up to date before you book the test, and take the correction you use every day. If your glasses are scratched, or your contact lenses are old and uncomfortable, replace them first. A poor result caused by an out-of-date prescription is one of the most avoidable reasons for a repeat test, and it is frustrating because the fault is not with your eyes at all, but with the lens in front of them.

Take your identity card, your existing driving licence, and any previous eye test results with you to the appointment, so that the ophthalmologist can see your history. Tell them honestly about any eye conditions, medication, or previous eye surgery, because that information can affect the way they interpret the results. Do not try to practise the Ishihara plates in advance, or to memorise them, because that will not help you pass a test that is meant to measure your real colour vision, and it can make the result unreliable. The best preparation is simply to turn up rested, with the right glasses, and with enough time to do the test without rushing. Allow at least an hour for the appointment, because the perimeter test and the full examination take longer than the short optician test.

Frequently Asked Questions

Do I need a special colour vision test for a lorry licence?
Yes, in effect. The group 2 eye examination includes a colour vision test with Ishihara plates, and it is assessed to a stricter standard than for a car licence. The ophthalmologist will record the result in your report.

Does colour blindness mean I cannot drive a lorry?
Not automatically. A mild deficiency may still be compatible with a lorry licence, depending on the degree and the assessment. A significant deficiency can lead to a refusal or to conditions, and the licensing authority makes the final decision.

How wide does my visual field need to be for a lorry licence?
As a guide, the horizontal visual field should normally be at least 120 degrees, with no major gaps in the central field. The ophthalmologist will measure it precisely with a perimeter test.

Is the lorry eye test done by an optician or an ophthalmologist?
For group 2 licences it is normally done by an ophthalmologist, who can assess visual acuity, colour vision, visual field and eye health in one examination. The standard optician test is usually not enough on its own.

How often do I need to repeat the lorry eye test?
The lorry licence is usually valid for five years, and it is renewed with a fresh medical and eye examination each time. Keep a note of your expiry date and start the renewal a few months early.

Conclusion

Colour vision and visual field in the lorry eye test are not minor details, and they are not there to catch you out. They are there because a professional driver needs to see colours reliably and to see what is happening at the edges of the road, day after day, in all conditions. If you understand what is tested, why it is tested, and how the results are used, you can approach the examination with confidence, prepare properly, and deal calmly with any result that is not a straightforward pass.

Book your ophthalmologist appointment in good time, take your current glasses or contact lenses with you, and keep a copy of the report for your own records. If you have a colour vision deficiency, or if you are worried about your visual field, talk to the ophthalmologist before the test, so that you know what to expect. With the right preparation, the eye test is just one step on the way to a professional driving licence, and not a barrier to it. For more on professional licences, see our guide to colour blindness and the lorry driving licence.