How do blue light glasses work?
Using anti-blue light lens film reflection technology, the glasses reflect harmful blue light, so the surface of the lens reflects blue light, and the substrate absorption technology of the anti-blue light lens will not reflect blue light. Anti-blue light glasses mainly reflect harmful blue light by coating on the surface of the lens, or absorb harmful blue light by adding anti-blue light factor into the substrate of the lens, to realize the blocking of harmful blue light. The blue light intensity emitted by the mobile phone screen was effectively suppressed by the use of anti-blue light glasses, compared with a portable spectrometer.
With the improvement of people's sports concept and sports protection concept, sports goggles are also widely welcomed. Safety glasses are worn during sports must have four major functions, safety (PC lenses), protection (TR-90 frame, soft and flexible), comfortable (non-slip nose pads and foot covers), and beauty (match sports and leisure clothing).
Sports goggles with shatter-resistant plastic lenses and side shields can prevent balls or sand from hitting the eyes. It can be fixed on the head without worrying about falling off during intense movements. The unique design of the rim of the frame makes the glasses very close to the human face and has a proper external isolation effect so that the human eye is not easy to be attacked by bacteria. The special lens has the functions of anti-fog, anti-shock, and ultraviolet rays, which is very suitable for outdoor activities.
How to Perform Glasses Measurements?
If there is no number on the temple of eyeglasses, you can perform glasses measurements by yourself. Now, we will show how to do that.
To measure the glasses’ size, you need to prepare a ruler or a tape first. To measure the frame width, measure the entire horizontal front of the frame, from the furthest extended point on either side. As for lens height, you should measure the vertical height of the lens. As for the bridge, you should measure the part that goes across the bridge of your nose. The temple arms include the front of the frame on either side and the rest behind your ear. The lens width is the horizontal diameter of one lens. So, when measuring these, you should be careful.
After that, you have measured the glasses frame size. If you want to know whether your face is right for this frame, you can read the post: How to Measure Face for Glasses Frames - 7 Steps
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Titanium frame machining is complicated.
The elastic modulus of titanium alloy is small, which is easy to produce large deformation, springback, distortion, and vibration in cutting, resulting in poor geometric shape and accuracy of the workpiece. As the surface roughness increases, the tool wear increases. The thermal conductivity of titanium alloy is poor and its thermal conductivity is small, 1/6 of that of 45 steel, so the high heat generated in processing cannot be effectively diffused. It is even harder to use titanium to make glasses. The frames are very thin and a lot of fine work is demanded. It's definitely a challenge for titanium, which is pretty difficult to work with. In addition, titanium alloy frames involve titanium alloy welding technology, which is more difficult.
What is a drop ball test?
The Drop Ball Test, known as the Basic Impact Test, is an Impact Test administered by the Food and Drug Administration to determine the safety of eyeglasses. Eyeglasses (sunglasses, exercise glasses, near-sightedness glasses, reading glasses, etc.) are a category of medical devices covered by the Food and Drug Administration. When glasses are exported to the United States or put on shelves on Amazon,eBay, and other platforms, they need to be registered by FDA. Besides the product listing, when the product passes the customs, the company may be asked to produce a Certification Statement of Impact Resistance stating that the product meets 21CFR801.410 Drop Ball Test requirements.
Should I wear glasses all the time for myopia?
Whether it is false myopia or true myopia, as long as a pair of suitable myopia glasses are used to complement the missing refractive power of the lens, the image of the object can fall on the retina again, and the distant objects can be seen again. Adolescents usually use high eye intensity and often wear myopia glasses, so that the ciliary muscles do not need to be 'so tired' to adjust, which can avoid further aggravation of pseudomyopia. However, adolescents are still in the process of development, and the degree of true myopia will gradually increase with age. Therefore, as the degree of myopia develops, refraction should be performed at regular intervals, and appropriate glasses for myopia can be prepared to prevent false myopia.
For adults under 200 degrees, because the degree is relatively light, they can wear glasses when they are looking at the distance and not wear glasses when they are near, which has little effect on vision. But for adults with high myopia, because of the weak adjustment ability of the eyes, it is recommended to wear glasses regardless of near vision or distance vision.
In summary, wearing myopia glasses is to reduce eye fatigue and prevents the occurrence of false myopia. Wearing myopia glasses from time to time may aggravate the degree of myopia, and wearing them often does not cause a burden on the eyes. Therefore, for myopia glasses, wearing them frequently is the most correct way to wear them.
h3>Types of Colorblind Glasses
Colorblind glasses come in different tints based on the type and severity of color blindness you have. If you have some eye conditions such as short sightedness or long sightedness, you may need a pair of prescription colorblind glasses. If you do not have other vision problems, you may just need a pair of non-prescription colorblind glasses. And the non-prescription colorblind glasses are cheap than the prescription ones.