Why do we need to wear glasses in summer?
Ultraviolet rays are strong in summer. Whenever you go out, you need sunscreen, sun protection clothing, and a sun umbrella. You want to wrap yourself up so that the ultraviolet rays cannot be recognized.
But there is a position of the body that is often overlooked by us. Yes, it is the eyes.
Ultraviolet rays not only damage the skin, but also always penetrate our cornea and lens, directly reaching the retina of the eye. Long-term chronic exposure to ultraviolet rays will not only cause damage to the retina, lens, etc., but also increase the number of cataracts, pterygium, and pterygium in the eyes. The incidence of macular degeneration.
Moreover, the summer sun is so strong that it can blind your eyes.
All kinds of strong light, stray light, and glare come from all directions, making people feel dizzy. It is even more unsafe if they are driving or riding a bicycle.
Therefore, I repeatedly advise everyone to wear sunglasses in summer!
Wearing a pair of qualified sunglasses can not only absorb and reflect ultraviolet rays, weaken the strong light, and achieve the effect of sun protection and comfort, but also effectively prevent ultraviolet rays from damaging the fundus of the eyes and prevent the aging of the skin around the eyes.
If it is summer or a day with strong sunshine, it is recommended that you wear polarized sunglasses, which can effectively filter strong light and block glare while protecting against ultraviolet rays.
Choose qualified and suitable sunglasses
Look at the tag logo
Qualified UV-resistant sunglasses must have national or industry standard certification marks. The product tag must indicate the implementation standard (QB 2457-1999 and GB 10810.3-2006) and product category (sun visors, light-colored sunglasses, special-purpose sunglasses).
For sunglasses with anti-UV function, the UV blocking rate must be clearly stated on the tag, such as "UV380/UV400" or "100% UV absorption".
Look at the CAT coefficient
CAT refers to transmittance, which is the proportion of visible light energy that can pass through the lens and enter the eye.
The stronger the light protection effect, the correspondingly "darker" things will be seen. Generally, Categories 2 and 3 are sufficient for daily use.
Look at lens quality
The power of the lens should meet the requirements for plain lenses, and the surface of the lens should be smooth without any wear marks, bubbles or other optical defects that affect vision. Lenses that are uneven or have marks or bubbles may cause discomfort such as dizziness after wearing them, so you should not buy them.
Don't buy cheap or substandard sunglasses from roadside stalls. Although the lenses are dark in color, the sunshade and ultraviolet filtering functions of sunglasses cannot be confused. Even completely black sunglasses, if they do not have UV protection function, will only dilate the pupil of the human eye, so that more UV rays will enter the eyes, which is more dangerous than not wearing sunglasses.
Look at the lens color
The lens color should be such that the color of the surrounding environment is not distorted. Before wearing sunglasses, first observe red, green, yellow and other colored objects, then put on sunglasses and observe the same objects. The colors of the two observations must not be color cast, otherwise the ability to identify traffic lights will be reduced. For brightly colored sunglasses, you should pay attention to this identification.
If you don’t consider special scenes and just wear it normally, dark gray, brown, and green gray are generally better. They absorb the spectrum evenly, cause the least color distortion, have the best color feeling, and can better meet the daily use of light.
Look at the polarization effect
Generally, large optical stores will be equipped with test cards to verify the polarization effect of lenses.
If consumers test by themselves, they can find an LCD screen and put the glasses horizontally against the screen. You can see that the lenses do not change at this time. Then turn the glasses and see that the color of the lenses becomes darker. Then turn them again and return to normal. This is polarization. lens. If there is no change no matter how you turn it, it is not a polarized lens.
Anti-glare polarized sunglasses are your first choice in summer
Regardless of whether the sunglasses are polarized or not, as long as they meet relevant national standards and have UV protection function, they can withstand UV rays.
So why do we still recommend everyone to choose polarized sunglasses?
In fact, the main difference between the two lies in whether they can effectively filter stray light and strong light.
You must know that when sunlight from all directions hits an object, the light will be re-reflected to form two types of horizontal and vertical light. The horizontal light will cause dazzling and random reflections. Even if you hold an umbrella or wear a sun hat, the light will pass through the road or the road surface. After reflection from smooth objects, a large amount will still enter the eyes.
At this time, when we feel dizzy, we need a pair of polarized sunglasses.
As the name suggests, polarized sunglasses have a polarizing effect. The lenses contain a polarizing film layer, which forms a structure similar to the fence structure of a blind. When wearing polarized lenses, when the vibration direction of a beam of light is consistent with the direction of the "louver fence", polarized sunglasses The lens absorbs all the light vibrating in the horizontal direction, leaving useful vertical light entering the eyes to prevent glare from damaging the eyes.
To put it simply, polarizers put a blind on the eyes, allowing only specific comfortable light to enter, suppressing interference from messy light sources, and allowing people to see real objects more clearly and comfortably.
Polarized sunglasses can be worn in daily life whether it is sailing, outdoor activities, driving, etc.
But I must remind everyone that you don’t have to pursue “polarized light” persistently.
Because if you need to wear sunglasses indoors or in low light, polarized glasses will make you unable to see the screen of your phone clearly. Therefore, if you do not need to spend more time outdoors, be exposed to strong sunlight, or have severe light sensitivity, you can also choose non-polarized glasses. Ordinary qualified UV-resistant sunglasses will also be enough.
