Sunglasses: sunscreen for the eyes!
Written by:Sunglasses are not just fashion accessories, but above all, real PPE, Personal Protective Devices. Glasses, in fact, have to protect our eyes from the sun and many other elements that could cause allergy. The Dr. Gustavo Brusasco, an ophthalmologist in Turin , explains how to choose them
How do sunglasses protect our eyes?
Sunglasses must allow adequate filtration of solar radiation and ultraviolet radiation . In addition, they also perform a "physical" eye protection task, protecting them from air, wind, pollen and dust. In subjects who suffer from allergies, therefore, glasses prevent the allergens from reaching the body and triggering the allergic reaction.
For those who wear contact lenses, they are indispensable when doing activities such as cycling or motoring: the opposite wind would dry the tear film and favor the dust inlet.
Sunglasses, therefore, are to be considered compulsory for both adults and children who have to expose to sunlight.
Children and sunglasses
Early age protection is crucial, even more so than in adults. Sunglasses are also available on the market even for children under 3 years old, colorful, soft and with a child-resistant resistance and safety.
Minimizing eye exposure to solar radiation slows the aging of eyelashes and retards the onset of disease. Prevention should be more stringent in conditions of particular exposure (for example, on snow) and during the summer, when the increase in ambient brightness and the amount of ultraviolet radiation can cause dazzle and eye fatigue.
How to choose sunglasses?
Choosing a frame that is not suitable for your face or too small lenses, which does not provide adequate protection against rays coming from the sides and upwards, spoils the benefits of wearing sunglasses. Side rays, in fact, easily reach the germinal epithelium of the crystalline, favoring the onset of cataracts .
The frame must cover the eye contour well so as not to allow the sunlight to pass sideways or upwards. In areas with strong solar irradiation (high mountains, glaciers, in the sea, etc.), you must always use very dark glasses, preferably with mirror lenses (it has more filtering power), with total ultraviolet protection and laterally closed .
At the same time, especially when driving, a frame that reduces the lateral field of vision due to too large or slow stitches that cause image distortion is not advisable. The choice of the frame is therefore weighted according to its own physiognomic characteristics and in relation to the type of protection we want according to the different requirements of sun exposure.
As far as the weight of the lenses is concerned, plastic lenses (polycarbonate) are now commercially available, with a much lower weight than conventional glass, with identical quality and UV protection. For those who want to maintain high-defects correction with glass lenses, there are photochromic lenses, which become progressively darker depending on the greater exposure to light.
For subjects with light irises and for those with special photophobia , polarized lenses have been designed that, in addition to stopping ultraviolet rays, increase contrast and improve perception of the image. Polarized lenses let you dazzle the glare of the reflection and see beyond the reflection itself, through the glasses of the car, the mist, the dazzling water.
Lastly, the latest technology is the melanin lenses, which completely absorb UVA and UVB radiation and 95% of the Blue Light. Synthetic melanin is able to enhance the action of natural melanin, protecting skin and eyes from the sun's radiation and preserving the skin around the eyes from premature aging due to exposure to the sun. Melanin also provides a perception of colors closer to the real one, with a consequent sharper and restful vision.
The color of the lenses
With regard to the color of the lens, there are no particular conditioning. It should be remembered, however, that intensely colored lenses alter the color perception and are for this reason little to guide or work while they are good for leisure:
• Yellow and Orange: Reduce transmission of blue rays, distort colors and accentuate contrasts. The lenses of this color are recommended for skiing or in conditions of low luminance and low contrast (in the case of fog, rain or covered sky).
• Blue: give more visibility to black and white, are recommended for those who have difficulty seeing closely and hypermetropins. I'm not advised, however, for driving and for all activities that require visual precision.
• Rose: They have a restful effect. They are suitable for sunglasses graduated.
• Gray: they are restful and do not alter the colors of the environment. They may, however, distort the perception of the distances, which is why they are little to guide. They are suitable for reducing glare in people who wear contact lenses.
• Brown: Highlight the green, offer excellent protection from harmful solar rays, but they do not protect in case of high brightness as in high mountains. They favor focus and are anti-dazzle (provided the tonality is not too intense). They are recommended for those with myopia problems.
• Green: They are restful, but may worsen the contrast of images. They are not recommended for myopia because they can distort the focus of objects, and recommend hypermetropies.
Tips to protect your eyes from the sun
Here are some notions to keep in mind when you are on vacation, both in the sea and in the mountains:
- Ultraviolet rays also pass through the clouds.
- Snow or white surfaces reflect more than 80% of the UV rays.
- UV rays increase with altitude.
- Under the umbrella, more than 50% of the UV rays are received.
- 95% of UV rays penetrate into the water.
- 50% of UVB rays arrive on the ground between 11.00 and 15.00. Sun exposure should be avoided in these hours to reduce UVD-induced photodata.
- The sand reflects up to 25% of the UV rays.
- The use of glasses with absorbent UV and hat lenses decreases head and eye irradiation, with a clear reduction in vision damage.
- The use of cosmetics or perfumes should be avoided before exposure to the sun: they may contain photosynthetic substances that enhance the damage of sunlight.
- Vitamins and mineral salts help combat the buildup of free radicals, which can damage the various eye structures, especially the retina. These antioxidants are vitamins A, C and E, betacarotene, lutein, zinc and selenium. They are found in oranges, kiwi, apricots, peppers, tomatoes, carrots and green leafy vegetables (spinach, broccoli, lettuce, etc.). It is advisable to consume large portions of these foods, which also prevent senile macular degeneration.
Editor Karin Moscow