Our eyes are by far the busiest sensory organ: we receive around 80 per cent of our impressions through them. We can recognise around 160 pure colours and around 600,000 shades of colour. Or what we think they are. From a physical point of view, everything colourful is not colourful, but merely light that falls into the eye in different wavelengths. There, the respective receptors pick it up and pass it on to the brain as a stimulus, where it is translated into a colour impression.
The original: This is how you would see the driving scene without glasses.
The images on the right-hand side simulate different glass colours and their effects
Red is created, for example, when short-wave (blue) and medium-wave (green) vibrations are swallowed up by an object and only long (red) waves reach the human eye. However, this does not create THE red. Depending on the environment and the composition of the light, the brain turns it into a strong cherry red or a pastel pale red.
The reason why we still don't run past our bike because it looks different at dusk than in the midday sun is because the eye functions independently of colour. It can recognise objects regardless of their lighting and quickly adapts to the respective lighting conditions.
This also explains why, after a while, you forget that you are wearing sunglasses. The eye has become accustomed to the fact that the world has a slightly different colour. A deceptive manoeuvre that cyclists can take advantage of. Because with the right filter - the right lens colour and darkening of cycling glasses - you can compensate for disturbing factors such as too much or too little light.
"The lens colour can enhance or dampen contrasts and also reduce or increase glare," says Gabriele Eckmann from the Offenbach-based specialist optician brillenladen.de. An example: an orange disc swallows a large proportion of the blue rays and lets green and red light through. The red-green channel in the eye is responsible for brightness, the contrasts appear brighter and the edges sharper. Conversely, grey lenses allow mainly blue light to pass through, the difference between light and dark areas is smaller. "This is energy-sapping for the body," explains Friedrich Einwich from Sportbrillen-Internetversand View factory. "Because the eye has to expend more energy to overcome the weakening of the light force."
It already has enough to do during a journey to adapt to the constant changes in light and shade. If you make its work even more difficult by wearing very dark glasses, it can no longer adapt quickly enough to sudden reductions in brightness, such as after entering a forest, because it receives too little light stimuli. And hardly being able to see anything for minutes on a public road can cost you your life in the worst case.
Even photochromic lenses, which change colour depending on the light conditions, are not a real alternative to light-coloured lenses for racing cyclists. "The lenses react to UV radiation, and this reaches the earth in all weathers," warns Einwich. "So the lenses may darken even when you don't need them, for example in cloudy weather."
The right anti-glare protection, i.e. how much the lens darkens, plays a similarly important role in sharp vision as the lens colour. "There is the right tint for every surface and all lighting conditions," says Uli Mößlang, master optician at Optik Freudenhaus in Munich, where he is responsible for the sports eyewear segment. In strong sunlight, for example, you can see well through brown lenses with a saturation of 85 per cent. "But you only need that on an Alpine tour at the height of summer," says Mößlang. In changing light conditions, as in our latitudes, glare protection of 60 to 80 per cent and yellow-brown or orange lenses are ideal. Incidentally, these should also lift your spirits - if cycling alone is not enough.
KNOWLEDGE
- UV protectionUV protection does not depend on the colour of the lens. The label "UV 400" or "100 % UV protection" means that the lens completely blocks ultraviolet light (UV), as it protects up to a wavelength of 400 nanometres. UVB rays have a wavelength of 280 to 315 nanometres, UVA rays between 315 and 380 nanometres.
- Transmission/absorptionThe glare protection index indicates how much light a pane lets through (transmission) or how much it absorbs (absorption). Generally also called glare protection. There are protection levels 0 (very light filter for evenings) to 4 (very dark filter for high mountains and glaciers). At our latitudes, categories 2 (up to 82 per cent light absorption, universal filter) and 3 (up to 92 per cent light absorption, for beaches and mountains) are the most suitable.
- PhototropePhotochromic or photochromatic lenses adapt to the light conditions. Depending on the UV radiation, they lighten or darken. Only suitable for cyclists to a limited extent (see running text).
- PolarisingPolarised lenses have a filter or coating that eliminates reflections on reflective surfaces such as water. Not very suitable for racing cyclists, as the image quality varies greatly from manufacturer to manufacturer and the lenses are often too dark.
- Anti-fogCoating to prevent the glasses from fogging up. The lenses are often more sensitive to scratches than uncoated lenses.
INTERVIEW
"It's not just about the colour"
TOUR: Professor Irtel, does the lens colour of cycling glasses influence the wearer's mood?
IRTEL: Naturally, warm colours such as yellow are more likely to convey positive moods than greenish and bluish colours. A filter, like a spectacle lens, changes the apparent distribution of colours in the environment. With a yellow filter, the number of yellow-coloured objects in our environment increases to a certain extent. As we generally perceive yellow as a warm, stimulating colour, our mood can also be influenced in this way.
TOUR: Could this be used for cycling? For example, lenses tinted in an aggressive red colour for racing?
IRTEL: Certainly not. For one thing, red doesn't make you aggressive, it stimulates you. Secondly, after a while you can no longer see a true red colour with red glasses. The most beautiful red is only perceived in a green or bluish environment and red glasses prevent this because they filter out these colours. In other words, a colour does not exist without other colours? You could say that. Brown light, for example, does not exist. A surface must contrast with other surfaces in order to appear brown. A spectacle lens can look brown when you hold it in your hand. If you put them on, you see a dark yellow colour. Colours and their effects can therefore only come into their own if there are colour contrasts.
