These are the sunglasses that the DGT recommends for driving

Vision is one of the most important senses when driving. According to the General Regulations for Drivers, to get behind the wheel, they must do so with a minimum binocular visual acuity of 0.5 (with or without correction). Even so, if the person achieves vision greater than 0.5 with glasses or contact lenses, it is essential that they use them in the car.

Therefore, when getting your driving license you must undergo a medical examination, and if you need glasses or contact lenses, this is reflected on the license. For example, if 01.01 appears above the number 14, it means that the person needs glasses to drive; if the number is 01.02, the driver needs contact lenses; while the number 01.06 indicates that you can use both.

But it must be taken into account that prescription lenses are not the only ones that are useful when driving. Sunglasses are not only a common accessory, they are a very useful item when we are in the car and the sun shines in front of us, endangering visibility. However, not all models are equally effective and there are even some that are harmful.

As the General Directorate of Traffic (DGT) explains in its magazine, according to Professor Amalia Lorente, from the Faculty of Optics and Optometry of the Complutense University, “when we put on sunglasses, the pupil opens and visual acuity decreases. If we are also ametropes, we are going to see much worse, because contrast is lost and sharpness is lost.

Therefore, there are a series of factors that determine which type best suits the driver's needs. It is important to know where they will be used, since depending on the luminance, experts will recommend a filter between 1 and 3 for daytime driving.

Of the three types of lenses there are: tinted or coated, polarized and photochromic, these first two are the most recommended. The tinted ones have embedded molecules in the lens that absorb radiation, uniformly or degraded. And those with coatings reflect light, reducing reflections, but are more delicate. On the other hand, polarized ones use this effect to eliminate reflections, although it must be checked that they allow the screens in cars to be seen.

What types of crystals are most recommended?

Regarding the color of the lenses, Lorente recommends, in general, using gray, brown or green filters “that do not alter the perception of color”, remembering that the brown ones “increase the contrast” and the green ones, “in addition to increasing the contrast , they reduce reflections and eye fatigue.

Pink lenses also increase contrast and reduce eye fatigue during prolonged use, while yellow lenses, because they block blue light, may be advisable in patients with retinal pathologies. The expert states that “there is no scientific evidence that a glass color improves vision with certain ametropias. Yes, a sensation of greater luminosity is produced, but the detail does not improve, greater acuity is not produced »and she attributes the comfort that some patients report to the «neural processing» of each individual.

Which sunglasses should not be used under any circumstances?

The DGT also points out that neither photochromic sunglasses nor those with category 4 filters should be used when driving. When entering a tunnel, vision can be seriously compromised, since they reduce the passage of light so much (category 4) that It is like driving blind, and the long adaptation time of photochromics (3-5 minutes) reduces vision.