The frames should be firm.
What kind of glasses are not easy to damage? It should be said that there are only two types of such frames: full metal frames full non-metal frames. However, be careful when choosing these two frames. Younger children prefer to move, and self-control is poor, so choosing a full non-metal glasses frame is appropriate. Although the middle school children are active, the self-control will be relatively strong, so you can consider the choice of a full metal glasses frame.
What is hard coating on lenses?
Lenses are mainly added in two kinds of film: anti-reflection film and hard film (and some manufacturers produce anti-fogging film and mirror film, but not common). The anti-reflective film is mainly by coating the front surface of the lens with multiple layers of transparent materials with different refractive index and thickness to reduce the excess reflected light on the surface of the lens, by using the principle of light interference. The film can be applied to both glass and resin lenses. The way of hard film plating is usually a soaking process. After many times of soaking and cleaning, soaking in an organic solution containing ultrafine silicon element for a certain time, and then keeping it at a certain temperature for 4-5 hours, the fixed polymerization process of the film has been completed. The surface wear resistance of CR-39 coating can be increased by 2-4 pH, which is similar to the hardness of optical glass lenses.
Data obtained by computer optometry alone may not be accurate.
The first thing is to go to the optometry store, or the hospital to do a glasses degree test, namely to get single optometry. The precision computer optometry has errors, and computer optometry is only used to measure separately monocular degrees. What we need is the best visual effect of the binocular match, so the exact prescription needs to be carefully confirmed by comprehensive optometry. Optometrists will ask everyone to try on the insert lenses again, and even need to repeatedly try on several degrees of lenses, in order to finally determine which degree is the most appropriate, because even the professional optometry data is only a rough range, only based on the data of glasses is not necessarily suitable for their own. You can use a focometer to measure the actual parameters of the glasses you are wearing. If you are still unsure of your prescription, it is recommended to fax, mail, or mail your prescription to the merchant when placing your order.
What Are Pinhole Glasses?
Pinhole glasses, also called stenopeic glasses, are plastic eyewear with hundreds of pinhole-sized perforations in place of lenses. Pinhole glasses are mostly used to improve refractive errors in the eye because they shield the eye from indirect rays of light which can distort vision. This would decrease the blur circle on the back of the retina.
When should I use blue light glasses?
Most of us spend a few hours a day in front of a screen. Because so many people work on a computer all day, many people wear blue glasses in the office. At the same time, many American high school and college students spend hours a day on their computers and could benefit from blue light glasses.
What are driving glasses?
Driving glasses refers to the glasses that are specially used for driving, with functions of anti-glare, anti-strong light, anti-rain and fog, anti-fatigue, and other functions. They are suitable for drivers in the day and night to wear glasses for vision protection, better-ensuring traffic safety. They are recognized as the driver's glasses, driver glasses.
How do anti-blue light glasses protect the eyes?
The anti-blue light glasses available on the market, no matter what type, etc., are mainly the difference in anti-blue light effect, light transmittance, and frame, which will affect the cost of glasses. Obviously, the lens is the most important of these. I think that it is basically enough to choose 30% to 40% anti-blue light glasses. It is good to cut off the harmful blue light. It is not necessary to completely eliminate the blue light so that the chromatic aberration will not be too large, the light transmittance is better, and it also has a certain anti-blue light effect.
Of course, to protect the eyes, it is not enough to rely on anti-blue glasses alone. The effect of anti-blue glasses is mainly to reduce the probability of eye diseases, and can not effectively relieve eye fatigue. Normal people between the ages of 20 and 40 blink about 20 times per minute. When you open your eyes and stare at a computer screen that changes rapidly, the number of blinks will be reduced to 4 or 5 times per minute, resulting in serious insufficient secretion of scum and dry eyes. Therefore, no matter how urgent the work is, you must pay attention to the rest of your eyes, close your eyes regularly, use eye drops when needed, and reduce the brightness of the screen as much as possible when looking at the screen. When the brightness of the screen is significantly higher than the ambient light It is easy to cause eye fatigue. Try to use it as little as possible in the dark. To be honest, it is more important to develop a good eye-using habit.