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Summer, Sun, Eye Protection

All about Sunglass Lenses


Article first published: May 2022

For many, sunglasses are a fashion accessory. But sunglasses have important functions besides the fashion aspect: They provide glare protection from the sun and, most importantly, protection from harmful UV radiation. Therefore, basically, everyone should have a suitable pair of sunglasses at hand, whether with or without a prescription, whether old or young.


Good to know: As early as 1924, ZEISS launched its first sunglasses on the market, the so-called UMBRAL lenses. They were the first sunglass lenses with a consistent tint. Today, the range of sunnies with diverse tints and extras is vast. This article explains the important things to consider when buying the next pair of sunglasses.

First of all, it should be said that there are sunglasses with prescription lenses and plano sunglass lenses. ZEISS has both variants in its product portfolio. That means wearing glasses doesn’t have to mean missing out on a pair of fashionable sunglasses and adequate protection, as they can customize their sunnies in almost any way imaginable. From progressive lenses to various refinements such as mirroring and polarization filters, to many modern colors and frames – eyeglasses wearers can choose whatever they want. Here are some tips on choosing the right prescription sun lenses.

Basically, optical sunglasses offer the same vision correction as conventional clear prescription eyeglasses. They are manufactured according to the values determined in an eye care professional's eye test, similar to a standard pair of glasses. What makes it different from normal glasses? Through tints in various levels and colors, the sunglasses also offer glare protection in addition to visual acuity – just like any other pair of sunglasses.

A vital purchase criterion: Full UV protection

When it comes to sun protection for the eyes, it's not just about glare protection, but also about protection against invisible ultraviolet (UV) radiation. Exposure to UV radiation without protection can lead to acute, medium-term, or even long-term damage to the body – and the eyes. This includes, for example, sunburn of the cornea or premature aging of the skin around the eyes. You can expect full UV protection from sunglasses from a specialist retailer. This applies to all ZEISS sun protection lenses, whether these are bought with or without a prescription. In fact, it has even been standard for all clear ZEISS lenses since 2018.

In the video, ZEISS expert Dr. Christian Lappe explains how UV radiation from the sun can harm the eyes.

What is important when it comes to the color and tint of the sunglasses?

When buying new sunglasses, the tint and filter categories are fundamental. This should correspond to the intended use of the sunglasses and personal visual habits. Sun lenses should not be too dark and not too lightly tinted either. For example, for a city walk, light tint levels in categories 1 to 2 are recommended, filtering out up to 57 percent or 83 percent of the light. For a vacation at the beach, category 3 should suffice. These lenses absorb up to 92 percent of the light and provide optimum glare protection on the water – or on very sunny days – reflections from the snow in the mountains, for example. Category 4 absorbs up to 97 percent of the light and is only suitable for special situations, such as hiking in high mountains. Driving a car is not allowed with such a dark tint.

The choice of color depends on when and under which circumstances the colored lenses are most often worn. In everyday life, while driving, during sports, or on special occasions? There are even some colors that have proven effects on our physiology and psychology. For those who plan to wear sunglasses frequently or for a stretch at a time, not too dark shades, and classic colors like green, brown, and grey are recommended as they are quite neutral. Personal light sensitivity and fashion considerations also play a role. The nearby eye care professional will be able to offer the best advice regarding this. They know what tint levels, color gradients, filter categories, and colors are available and what these are suitable for. They know what tint levels, color gradients, filter categories, and colors are available and what these are suitable for.

And have you ever wondered how the color gets into the sunglasses? There are mainly two ways in which lenses are tinted. While sometimes the material itself is already colored, in other situations clear lenses are dyed in a tinting bath. This depends for example on the used material and if the lenses are with or without prescription. 

Sunglasses in many different shades
The choice of color depends on when and under what situations the colored sunlenses are most often worn.

Mirror coating – making a fashion statement

Style- and trend-conscious people place a special value on the appearance of their sunglasses. No problem, because sunglasses can easily be refined with various mirror coatings – whether these sunglasses are with or without a prescription. The ultra-thin vacuum layers are simply vapor-deposited onto the front of the lenses. These layers are optimized in their sequence, texture, and thickness. The reflection of light on the lens surface is enhanced and literally reflected in a specific, defined intensity and color. In addition to making a fashion statement, such mirrored sunglasses also reduce the intensity of light in extreme lighting conditions.

Mirrored green sunglasses
Sunglasses with mirrors are a fashion statement and help to protect the eyes from UV.

Polarizing lenses: reduce annoying light reflections and improve contrast vision

Who often travels in a car or anyone practicing water sports should also consider polarizing sunglasses. How do they work? Glare from reflected light, caused by sunlight on wet roads, snow, or water, significantly affects visual performance and can even lead to not recognizing dangerous situations in time. Special polarizing sunglasses reduce this annoying light reflection and improve contrast vision. With – if needed - the correct visual acuity and specific tints in the sunglasses, it is easier to recognize dangerous situations in road traffic. This is achieved, for example, by ZEISS DriveSafe lenses with special tints and polarization filters. But polarized lenses such as ZEISS SkyPol also ensure that significantly more of the surroundings can be perceived. For example, during water sports such as fishing, they make it easier to see fish under the water's surface. In contrast, the surface reflection usually means that, with standard lenses, only the water’s surface itself can be seen and not fish beneath.

Intelligent: Sunglasses with automatically adapting tint

People often need two pairs of sunglasses: one less tinted and one darker. Especially those who are active outdoors, enjoy strolling in the city, or are looking for more comfort in everyday life may consider sunglasses with a tint that adapts to the different light conditions. ZEISS AdaptiveSun lenses, for example, have a base tint of 60 percent when there is no sunlight, such as in a retail store, and darken up to 97 percent when there is extreme light intensity. They adapt automatically to all light conditions and ensure broad comfortable vision: outdoors in the sunshine or on cloudy days and indoors. They are also available with a gradient tint, which makes it for example easier to read a menu in the garden of a restaurant. Constantly putting on and taking off sunglasses has thus become a thing of the past.

What to look for when buying sunglasses for children?

So many parents do everything to protect their children from the sun but often forget about the eyes. Children's eyes are in fact very sensitive to UV radiation and therefore also sensitive to the dangers it poses. Studies suggest that by the age of 20 we might have already received 50 percent of our lifetime estimates of UV exposure. 1 Therefore, kids should also wear sunglasses as often as possible. Of course, a pair of children's sunglasses must also protect against UV radiation up to 400 nanometers. In addition, kids' sunglasses should be robust and fit well. The nearby eye care professional can provide consultation on this too.

Mädchen mit Sonnenbrille auf Wiese im Sommer

Source:

1) Green, A. C., et al. (2011). Childhood exposure to ultraviolet radiation and harmful skin effects: epidemiological evidence. Progress in biophysics and molecular biology, 107(3), 349-355 / Meta Study, taking several studies into account


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Get in Touch with Us

Joachim Kuss
Head of Communications: General topics and Sustainability
Mail: joachim .kuss @zeiss .com

Phone: +49 (0) 151 42112288

Maria Conrad
International PR: Instruments, Tools and Digitalization
Mail: maria .conrad @zeiss .com

Phone: +49 (0) 7361 591-1378