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Sunglasses: Which ones protect against UV radiation?




 

Sunglasses are designed to protect the eyes from dangerous UV-A and UV-B rays. Which ones offer sufficient protection? What is important when it comes to UV filtering, shape and quality of the lenses?

Sun rays can damage not only the skin, but also the eyes. Possible consequences of UV-A and UV-B rays include inflammation of the cornea or conjunctiva, clouding of the lens (cataract) and even cancer. Experts also suspect a connection between the sun’s rays and the formation of the Macular degeneration. To prevent damage to the eye, you should wear sunglasses in strong sunshine. This also applies to children, because their eyes are particularly sensitive to UV radiation.

How sun rays harm the eye

In the eye, the lens absorbs most of the UV-A and UV-B rays. In the process, proteins change so that clouding of the lens can occur in the long term. A small part of the long-wave UV-A radiation hits the retina through the lens. If extremely strong rays occur unfiltered for more than 30 seconds, a photochemical reaction occurs: the photoreceptors are destroyed. For example, a direct view of the sun, for example when observing a solar eclipse, can lead to acute, irreversible damage in seconds. In the case of so-called snow blindness, the cornea burns within hours.

But even a so-called sunburn in the eye, which usually heals after about one to two days, is unpleasant. Typical symptoms are red, burning or aching eyes and blurred vision after staying in the sun. If sunburn is suspected, it is better to consult a doctor to avoid permanent damage to the eye. Ointments and eye drops can relieve symptoms.

UV radiation on the water particularly high

The pier on the beach on Usedom © colourbox

At the sea, good sun protection for the eyes is important because the water reflects the light.

Especially on the beach and in the water you should therefore protect the eyes well. The danger is particularly great in water sports: The so-called Surfer’s Eye is a proliferation of the conjunctiva, which often arises as a result of the intense sunlight on the water. Because there the light not only comes from above, but is reflected by the water surface from all sides. As a result of the extreme UV exposure, the conjunctiva proliferates beyond the cornea. If the growth becomes too large, it must be removed.

Filtering: Pay attention to UV400 standard and infrared protection

For effective sun protection, sunglasses should filter out all UV rays up to a wavelength of 400 nanometers. Such glasses can be recognized by the inscription “UV400” or “100 percent UV protection”. The marking assures the buyer that the glasses protect the eyes from harmful UV rays.

In addition, additional infrared protection is recommended, especially for places where solar radiation is particularly intense, such as the sea or in the snow. The CE mark, on the other hand, must be worn by all sunglasses sold in Germany: it indicates that at least 380 nanometers of UV protection is available and that the product complies with the applicable EU directives. However, this information is not verified by any independent body.

Shape: Sunglasses should completely cover eyes

Sunglasses should sit in such a way that they cover the eyes as completely as possible and also prevent irradiation from the side. It should also be as close to the eyes as possible. Wider brackets protect against stray light from the side.

Dark tint does not mean UV protection

Stall with sunglasses © Fotolia.com Photo: maho

Sunglasses are available in a wide variety of colors and tints – with and without mirroring.

The tint of the lenses says nothing about the UV protection. But bright light dazzles the eyes and makes them tire faster. The brighter the light, the darker the glasses should be. Manufacturers distinguish five categories from 0 for very low tint to 5 for very dark. High-quality glasses contain a polarization filter that reduces light reflections and ensures a clearer image. The color of the lenses is a matter of taste. Orange lenses make everything green look richer and increase contrasts. They are not suitable for road traffic because they distort signs and warning lights.

agonyTesting the quality of the glasses: Are lines distorted?

The quality of the glasses is reflected, among other things, in the fact that they have no inclusions or irregularities. Objects must not appear distorted or curved, as this can lead to headaches. A simple test before buying: Hold the glasses with some distance in front of the face and aim for a straight line. With slight movements of the glasses, the line should not distort.

Uv protection is often not sufficient for older sunglasses

Be careful with older models of glasses: They often allow a large part of the UV rays to pass through and should be replaced, because behind dark lenses our pupils open and thus let more rays into the eye. The retina is then at their mercy. It is better not to wear sunglasses than one with poor UV protection. Whether an existing pair of sunglasses really protects can be measured by the optician.

Further information

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Arjun Sethi
Passionate guitarist, gamer and writer. Lives for the perfect review, and scrapes texts until they are razor-sharp.
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