The objective of this article is to try to clarify some controversial aspects of the requirements demanded by current law to obtain or renew a driver's license, referring to vision. The points we will cover are:

Visual requirements to obtain a driving license

The visual requirements for the driver's license are:

1. Visual acuity (AV)
2. Campo Visual (CV)
3. Contrast Sensitivity (SC)
   

Specific considerations to be noted on the driver's license

The specific vision considerations that must be specified on the driving license are:

1. Cataract surgery (Aphakia and Pseudophakia)
2. Refractive surgery: myopia, farsightedness y astigmatism
3. Alterations of the Eyelids
4. Alterations of the ocular motility: Squint, Diplopia y Nistagmus
5. Degenerative diseases with loss of vision
6. Glaucoma
7. Acute loss of vision in one eye

The truth is that there is some controversy when interpreting the law. The main problem that we have detected is that the majority of drivers and centers dedicated to driving, such as driving schools and check-up centers, are based on the guide published by the DGT (Guide to health advice in occupational road safety), a very complete guide that establishes multiple recommendations and that is based on the current law but does not include all the points that are specified in it, even in some topic such as the time that must elapse without driving after a refractive surgery, it's wrong.

The DGT guide is a guide, as the name implies and if we want to know the regulations in detail, we must go to BOE Nº 220 Sec. 1, p. 77421, to the PRE / 2356 Order of the 3 of September of the 2010, which includes the modification of Annex IV of the General Regulations of Drivers, approved by Royal Decree 810 / 2009, of 8 of May, and which entered into force the following day of its publication (4 of September of the 2010). An attempt is made to equate Spanish and European legislation, so that the driving rules are the same in all the states of the European Union.

The truth is that the law, as it appears in the BOE, is not easy to interpret, especially for a layman on the subject, that is why we have tried to capture the most relevant aspects in a practical way, establishing two sections, one of general considerations and other specific aspects, such as what to do after eye surgery or certain diseases that affect vision. In both cases, differences are established for non-professional drivers (G1) and professional drivers (G2).

Visual requirements for driving license

Vision is measured by studying 3 main factors, visual acuity (VA), campor visual (CV) and the contrast sensitivity (SC), of which visual acuity is the most important and where a minimum is required in a more specific way since in the CV and SC they are not so clear and in many cases it will depend on the ophthalmologist's criteria, as we will see later. ahead.

Visual acuity

Visual acuity measures the amount of vision in static conditions, assuming that the ideal would be to establish VA in dynamic conditions, such as occurs in real life. VA is measured with or without correction and when optical correction is required, its use is mandatory while driving, although without it the minimum specified below will be achieved.

1.  AV in the G1: Binocular visual acuity is required (with both eyes at the same time), equal to or greater than 0.5, with or without optical correction, so that if one eye sees less than 0.5 but with both this minimum is reached, it can be obtain the license. The eye that does not reach 0.5, should not have a vision less than 0.1, if this happens, that person is considered to have monovision, you only see with one eye and in these cases you can obtain a driver's license or its extension but it must be evaluated according to the "Restriction Conditions" that the law includes and that we will talk about later.
2. AV in G2: the law requires a minimum vision of 0.8 in one eye and 0.5 in the other eye, with or without optical correction, and this must never exceed 8 diopters. In G2, monovision is not allowed (VA < 0.1 in one of the eyes).

Campor visual

Basically, the isoptera or peripheral margins and the scotomas central, that is to say the areas of central vision when we look straight ahead.

1. CV in G1: The CV must not have alterations when it is taken under binocular conditions, with both eyes at the same time and the central region must not present absolute scotomas. In case of presenting it, it must be evaluated with the "Restriction Conditions". These requirements, which the law considers very specific, are not so specific when it comes to performing the CV test, since most ophthalmological centers use a technology, campcomputerized imetry, which performs the CV of each eye separately and there is no binocular CV program, a fact that poses a difficulty when evaluating the CV in special pathologies. In G1, certain QoL alterations are allowed that must be evaluated by the ophthalmologist and it will be the ophthalmologist who determines the limitations that he deems appropriate.
2. CV in G2: The CV is evaluated in each eye separately and here the law is clear, there can be no central scotomas in either eye. It is not as specific when evaluating peripheral limits.

Contrast sensitivity

Contrast sensitivity measures vision conditions in low light, mesopic vision, emulating dusk-night driving, and is carried out without and with glare, with a spotlight in front that attempts to reproduce the headlights of a car driving in the opposite direction. contrary.

1. SC at G1: The law only specifies that there should be no significant alterations in mesopic vision and vision recovery from glare. The criterion of "significant alterations" is left to the subjective interpretation of the ophthalmologist, since the minimum vision is not specified, as it happens in visual acuity and could occur in the same way in CS, taking vision under certain level criteria. ambient light and dazzling light, just as ophthalmologists do in this type of examination.
2. SC at G2: There are no differences with the G1, the same requirements apply.

Restrictive conditions and visual limits for the card

Visual acuity

Visual acuity: In the G2, no restrictions (exceptions) are allowed, that is, the minimum requirements mentioned above must be met to maintain the license or renew it. The restrictive conditions only apply to non-professional drivers, G1. It refers to people who have lost the vision of one eye or it is less than 0.1, a situation that is called monovision or monocular vision (they see with only one eye).

The law states: "Those affected by monocular vision with visual acuity in the eye better than 0,5 or greater, and more than six months old in monocular vision, may obtain or extend permission or license, provided that it meets the other visual abilities. When, due to the degree of visual acuity or the existence of a progressive ocular disease, the periodic examinations to be performed were for a period shorter than the normal validity of the permit or license, the period of validity will be determined according to medical criteria. Exterior rear view mirror on both sides of the vehicle and panoramic interior mirror or, where appropriate, rear-view mirror adapted. "

As we can see, in the case of non-professional drivers (G1), the law allows driving with vision in only one eye and as long as the eye with vision is equal to or greater than 0.5 and leaves it to the ophthalmologist's discretion to consider that the rest of the visual functions, campor visual and contrast sensitivity are good enough not to have an accident. Depending on the situation of each person, it is once again up to the discretion of the ophthalmologist who performs the review to include any restrictions, such as setting speed limits or driving only in daylight, avoiding the night, as well as the duration of the license, the time when you should carry out new revisions, especially in the case of degenerative diseases with a tendency to worsen.

Campor visual

Campo Visual. The Law is strict in specifying that restrictions are not allowed in the CV in terms of a significant reduction of the peripheral limits and the presence of absolute notches in the central region for G1 and G2 conductors, however it admits that a conductor does not professional (G1), may have CV alterations as a result of a disease such as glaucoma o retinal degeneration, which could cause areas of relative scotomas or a decrease in retinal sensitivity, provided that the ophthalmologist considers that it is not to a significant degree to impede driving.

Once again, the possibility of continuing to drive or obtaining the certificate to process the license remains in the hands of the ophthalmologist's subjectivity.

Contrast sensitivity

Sensitivity to Contrast. The law is again categorical in not admitting restrictions regarding the SC for professional drivers, they must comply with the requirements set to continue driving, while leaving an open door for non-professionals. The ophthalmologist should be the one who evaluates the situation of each person, establishing the limitations they deem appropriate as well as the duration of the license until a new review.

Specific considerations of the view for the driving license

Cataract surgery and driving license

In the interval of intervention of one eye and the other, it is not clear if you can continue driving. The guide of the DGT seems to indicate that it is possible and that it would only be necessary to take precautionary measures but if we go to the law, 1 requires a month after surgery and that the ophthalmologist specifies that vision has recovered within the limits that we have seen for the AV, CV and SC, that is, if the interval between surgeries of the two eyes is less than 1 month, we understand that you can not drive.

After cataract surgery, of one or both eyes, you must wait a minimum of 1 month in the drivers of the G1 and 2 months for professionals, G2, and thereafter, if the vision levels required by law are reached, with the report of the ophthalmologist can obtain or renew the driver's license for a maximum period of 3 years, both for non-professional drivers and for professionals. If the ophthalmologist considers that the recovery is not correct, he may decide to establish limitations in the driving conditions (speed limits or others) or recommend that the duration of the license be less than 3 years.

If optical correction is necessary after surgery to improve vision, it will be mandatory, even if vision with correction exceeds the minimum required by law. Intraocular lenses are not considered corrective lenses.

The renewal of the driver's license will be for a maximum of 3 years, both for G1 and G2, according to medical criteria.

The term aphakia refers to the lack of crystalline, a fact that occurs when operating the Cataracts without implanting intraocular lens (IOL), whereas if the IOL is implanted, then we call it pseudophakia. In both cases, it must be remembered that professional drivers cannot use glasses with more than 8 diopters, a fundamental fact when considering cataract surgery. In aphakics, optical correction usually exceeds 12 diopters, achieving good vision, but they would not be allowed to renew the license, therefore it is necessary to consider the implantation of an IOL, so that if there is some graduation, it does not exceed the limit of 8 diopters.

Refractive surgery (myopia, hyperopia and astigmatism) and driving license

After this type of surgery there is a vision recovery period, which varies greatly depending on the technique performed and according to each patient, and can range from 24 hours to several weeks.

The point that specifies the period required to renew the license is where there is more discrepancy between the DGT guide and the law. According to the DGT it is not necessary to wait more than 24 hours, as specified in its point 3.B: Effects of treatment on driving, however, in the law in the section 1.1: Visual acuity. Exploration, When referring to refractive surgery, for non-professional drivers, G1 states: "After a month of refractive surgery, providing a report of the intervention, the permit or license may be obtained or extended, with a maximum validity period of one year. After one year from the date of the intervention, and taking into account the presurgical refractive error, the current refraction and the possible existence of unwanted side effects, the ophthalmological criterion will determine the subsequent period of validity. "For professional drivers, it only changes in that the waiting period is 3 months.

We see that according to the law you have to wait 1 month for G1 and 3 months for G2, and that it is not necessary to pass a new review, only the ophthalmologist's report is required, yes, the duration time is 1 year , after which the review will be necessary in an accredited center and will depend on the ophthalmologist who performs the review, the possible limits and restrictions as well as the duration of the license.

Alterations of the Eyelids

The law specifies: “Ptosis or lagophthalmos that affect vision are not allowed within the limits and conditions indicated in sections 1.1 and 1.2 corresponding to group 1”. The ptosis is the upper eyelid droop and it can be a "screen" that prevents light from entering the eye, affecting vision. The lagophthalmos is the fall of the lower eyelid, generally after facial paralysis or other pathologies, causing problems in the distribution of tears and ocular dryness, making vision difficult.

You cannot drive with alterations in the motility of the eyelids that produce a decrease in vision below the minimum that we have seen previously, although the law does admit that there may be a disorder that the ophthalmologist considers does not seriously impair vision and Consider that you can drive, with some restriction or with a temporary duration of the license.

Motility of the Eyeball: Strabismus, Diplopia and Nistagmus

People affected by squint or before a neurological process that causes alterations in the motility of the eyeball, they also have restrictions that the law contemplates.

In the cases of squint (ocular deviation) and Nistagmus (pendulum movement of the eyes), driving is allowed as long as the vision, in its three facets, AV, CV and SC, is within the limits required by law, although a report from the ophthalmologist will be necessary, which may suggest certain limitations in driver's license, depending on the examination of the stereopsis, visual fatigue, presence of phoria, torticuli, or other signs and symptoms. The duration of the license will depend on what the ophthalmologist considers for non-professional drivers, while it will be a maximum of 3 years for professionals.

The law is sharp with the diplopia in professional drivers, it does not support any restrictions, they cannot drive with diplopia, while in non-professional drivers, it states: "Diplopia will only be allowed at ophthalmological criteria as long as they do not manifest in the central 20º of the campor visual and do not produce any other symptomatology, especially visual fatigue. In those that have recently appeared, a period of at least 6 months without driving must pass. In case of obtaining or extending the permit or license, the maximum period of validity will be three years. When the diplopia is eliminated by the occlusion of an eye, the restrictions of monocular vision will be applied. "

Degenerative diseases with loss of vision

The law allows driving as long as the minimum requirements for AV, CV and SC are maintained, although it specifies that the ophthalmologist must be the one to establish, in each case, the possible restrictions as well as the periods of validity of the driver's license, both for both G1 and G2 drivers.

When the vision is below the minimum required by law, it does not admit restrictions or exceptions for professional drivers, G2, it is clear, they can NOT continue driving.

Glaucoma and driving license

For those drivers who suffer Glaucoma (involvement of Optic nerve generally due to increased tension), the law also establishes certain measures, in this case the same for groups G1 and G2: "When even reaching the minimum levels of vision required by law (sections 1.1 to 1.6, both inclusive), the Intraocular pressure is above the normal limits, possible associated risk factors must be analyzed and a periodic control will be established at the ophthalmological criterion.”

We see that again it is the ophthalmologist who in each case must establish the possibility of continuing to drive or establish restrictions and shorten the validity period of the license. The key point is the affectation of the campor visual (VC), if there are no central scotomas or a significant reduction in peripheral isoptera and retinal sensitivity is correct, as well as the glare vision test, driving may be allowed, but when these points deteriorate, risk should be evaluated of driving.

Acute loss of vision in one eye

This is one of the sticking points that the law does not make entirely clear to professional drivers. In section 1.4: Acute impairment of visual capacity, in the G1 it is specified: “After an important and sudden loss of vision in one eye, an adaptation period of 6 months without driving must pass, after which the permit or license can be obtained or renewed providing favorable ophthalmological report.” , and in the G2 it reads: "Idem 1 group", so it could be thought that the professional drivers of the G2 can drive but, in previous points, in the reference to visual acuity (1.1: Visual acuity. Exploration), it is very clear that in the case of G2, monovision is not allowed, that is, the eye with worse vision should never have a VA less than 0.1 and there are no restrictions or exceptions.

I hope that the points discussed can clear up some of the doubts about the visual requirements for driving. I do not want to end without insisting on the importance of good vision for safe driving. Optometrist and ophthalmologist reviews are necessary to detect possible alterations and, above all, to ensure that we use the appropriate optical graduation.

Also insist that people with visual disturbances who, even with optical correction, do not achieve good vision can benefit from therapies and exercises that can improve visual conditions, both in terms of quantity and quality, as well as reflexes, reaction time and vision. peripheral vision and glare, especially after surgery, degenerative diseases or simply with age-related loss of skills.