Which sunglasses are right for age-related macular degeneration?
Sunglasses are a must in summer. They are not only an attractive accessory, but they are also important for protecting the eyes from possible damage caused by increased exposure to the sun. Both cataracts and age-related macular degeneration (AMD) are among the resulting damage. If AMD is already present, suitable sunglasses can help improve vision and protect the eyes. But which sunglasses are the right ones? Should you use light-tinted lenses or dark ones? What role does the color of the tint play? Are contact lenses sufficient? Follow our step-by-step guide to your perfect sunglasses.
tint for relaxed eyes
Sunglasses protect the eyes from bright, dazzling light and from the UV radiation contained in sunlight. Glare protection is primarily a question of comfort. The tint of the glasses means less light falls into the eyes, making vision more relaxed and making the eyes less likely to tire. Protection from UV radiation is more important for eye health: just like the skin, the eyes can also be damaged by the high-energy radiation. Since the damage only becomes noticeable after many years, the importance of wearing suitable sunglasses is unfortunately still too often underestimated.
Which part of the light is harmful?
UV radiation is a part of the sun's radiation outside of visible light. The so-called UV-A and UV-B radiation are relevant for sun protection. Almost all UV-B and a large part of UV-A radiation is absorbed in the lens of the eye. However, this changes certain proteins in the lens, which can lead to progressive clouding of the lens, a cataract. The more deeply penetrating UV-A radiation reaches the retina and is considered a major factor in age-related macular degeneration. UV-A radiation covers the wavelength range from 400 to 315 nm, UV-B radiation from 315 to 280 nm. The visible range of light begins above 400 nm. A good sun protection must therefore filter the entire wavelength range below 400 nm.
Step 1 – Pay attention to UV protection
Good sunglasses should have sufficient UV protection. What many people don't know is that UV protection is not related to the tint of the glasses, but can be just as invisible as UV radiation. Whether sunglasses have sufficient UV protection can be recognized by two symbols, the so-called CE symbol and the UV-400 symbol. The CE symbol is based on an EU directive, because sunglasses are personal protective equipment and are therefore standardized. However, this standard only specifies protection up to 380 nm. In addition, many sunglasses are marked with the UV400 or 100 percent UV protection symbol. This marking is not standardized, but according to the Federal Office for Radiation Protection, it generally indicates sufficient protection. Glasses should still be bought from specialist retailers rather than at the supermarket checkout. Many opticians also have devices that can be used to check the actual effectiveness of UV protection.
2. Choose the right glasses size
Good sunglasses should cover the eyes as completely as possible so that no light can hit the eyes from the sides. The tint of the sunglasses dilates the pupils and allows more light to enter the eyes. The size of the glasses can therefore be chosen generously. The glasses should also be so close to the eyes that the eyelashes just do not touch the glass. Models that are slightly curved around the head or wide temples help reduce the light coming in from the side.
3. Choose the right shade
The tint of sunglasses is divided into five categories.
- Cat 0: 3 – 20 % tint
- Cat 1: 20 – 57 % tint
- Cat 2: 57 – 82 % tint
- Cat 3: 82 – 92 % tint
- Cat 4: 92 – 97 % tint
Tints in categories 0 and 1 are suitable for indoors and overcast days, especially for people with sensitive eyes. Category 2 includes the all-rounders for Central European summer days. Glasses with this tint can also be worn in changing light conditions, such as when driving or in the forest. In more southern regions, it is recommended to use tints in category 3. Glasses tinted in this way also offer sufficient protection on the beach or in the mountains, where the intensity of the sun is increased by the reflective environment. Category 4 is the highest protection class. Highly reflective surfaces such as water or snow can make protection in this class necessary. Tints in this category are so strong that they are no longer permitted for driving.
4. The color of the lenses
The choice of lens color is largely a matter of taste. However, since colored lenses always filter out a certain part of the color spectrum, not all colors are equally suitable for every situation. Blue lenses, for example, filter out the red part of the light. This means they are not suitable for driving, as traffic lights and warning signs are much harder to see. However, they can be helpful for sporting activities, as they improve contrast perception, just like red and yellow lenses. Gray lenses offer the most natural color perception. They are therefore suitable as everyday lenses for every situation. Green and brown lenses also reproduce colors as naturally as possible and are therefore suitable for everyday use.
5. Special glasses and contact lenses
Eye diseases such as AMD often lead to increased sensitivity to glare. Edge filter lenses can help against this, as they completely filter out part of the short-wave blue light spectrum. Blue light is high in energy and therefore particularly contributes to the glare effect. The perception of contrasts is also significantly improved. Depending on the choice of filter, the color fastness can even be largely retained, and the glasses can therefore also be worn in traffic. Working on monitors or displays is also more pleasant for the eyes, as they are less strained by the blue light from the devices. Polarized lenses can also be helpful with AMD. A special crystal layer on the glasses ensures that light coming from the side is largely absorbed. Most of the light that reaches the eye comes from the direct line of sight (i.e. from one pole). Reflections from puddles, water surfaces or the windshield largely disappear and contrasts are perceived more sharply. This not only improves vision in difficult conditions, but also keeps the eyes more relaxed. The only disadvantage is that LCD displays on cell phones or navigation systems can appear black because they already work with polarized light. Contact lenses with UV protection are now available. Since contact lenses do not naturally cover the entire eye, they are only suitable as additional sun protection. To protect the entire eye and the sensitive eyelids, additional sunglasses are required.
This is what the ideal sunglasses look like
Especially in the summer months, you should always have sunglasses to hand. When working outdoors, they are even considered protective equipment and must therefore be provided by your employer. Even if your personal taste is more subtle, the ideal sunglasses for everyday wear are large, black-tinted and have UV protection up to 400 nm. Outside of traffic, there are no limits to your personal taste when choosing your lenses.
Is the eye unprotected without sunglasses? Natural mechanisms help.
The human eye has several mechanisms to protect itself from too much sunlight. Firstly, there are the eyelashes. Like a small curtain or a peaked cap, they absorb a small part of the sunlight coming from above without restricting the field of vision. By squinting the eyelids, the amount of light can be reduced even further. How much light actually reaches the retina is ultimately determined by the opening and closing of the iris. Proteins in the pupil and the subsequent vitreous body absorb some of the harmful UV-A and UV-B radiation. A final protection for the retina are yellow pigments that are stored in the area of the macula and give it its name: macula lutea - the yellow spot. The function of the pigments is presumably to absorb the remaining UV radiation.
