As the saying goes, what is expensive is not necessarily the best, but what suits you is the best. However, when you are faced with a wide range of lenses on the counter, most of you will be blinded and caught in the tangle of choice. In the end, they are led by the shopkeeper’s nose and choose a lens that is expensive but not necessarily suitable for them in the enthusiasm of the shopkeeper. Spherical lenses vs aspheric lenses When you go to an optician to get glasses, the clerk will often recommend aspheric lenses. So what’s so great about aspheric lenses?
There is no denying that compared to spherical lenses, aspheric lenses have the following unique advantages.
● aspheric design makes the vision more realistic and natural, with a wider field of view and reduced eye fatigue after vision.
● flattening of the surface curvature of the ophthalmic lens, thus reducing magnification, which will give a natural look to the eye, with no particularly noticeable changes and increased aesthetics.
● thinner and lighter eyelenses.
● The curvature of the ophthalmic lens matches the curvature of the rim, making it safe to fit.
However, this does not mean that everyone needs to go with aspheric lenses.
For people with high myopia or high astigmatism or presbyopia, aspheric lenses are recommended. The aspheric lenses are lighter, thinner and more beautiful than the lenses with the same refraction and the same prescription. At lower diopters, this difference is not as pronounced.
It is important to note that improperly fitting aspheric lenses may result in worse visual quality than improperly fitting spherical lenses.
In addition, the accuracy of the optometry, the precision of the edge fitting, and the availability of wear adjustments can all have an impact on the wear of aspheric lenses. When fitting aspheric lenses, it is necessary to measure the pupillary distance and height of one eye, as well as to adjust the front tilt of the frame.
Office white-collar workers should use lighter color tinted lenses
Summer is here, the shopkeepers have another trick – recommending dyed lenses to customers because they “can protect the eyes from UV rays outdoors.”
Is this true or not? There are so many colors of tinted lenses, should I buy dark or light ones?
In fact, depending on whether the lenses are dyed or not, they can be divided into ordinary white lenses, fully dyed lenses and color-changing lenses.
Ordinary white lenses are those without coloring, discoloration or polarization. Fully dyed lenses, also known as colored lenses, are made by adding chemicals to ordinary white lenses to make them different colors.
Color-changing lenses are ordinary white lenses with different photosensitizers, such as silver halide, copper halide, chromium halide, etc. Under light, the photosensitizers decompose and the lenses take on different colors, such as teal, teal gray, gray, light yellow, orange, blue color-changing glasses lenses, etc.
First of all, the choice of lens color depends on personal needs, specific wearing environment, and appearance. If you work in the hot sun, such as traffic police, geologists, etc., you can choose darker lenses; if you are an office white-collar workers, in the indoor light environment, you can only use the lighter color lenses.
In addition, there are some rules of prescription glasses, the shopkeeper will not tell you: ● When using dark glasses, you can only use lighter lenses.
● When using dark glasses lenses, the color of the frame should be slightly darker than the glasses lenses.
Eyeglass frames should be wider rather than narrower.
● Children and teenagers in the growth period should not wear dyed lenses, especially dark lenses, for a long time. This is because the amount of light entering the eye drops after wearing such glasses, and the normal development of vision is done under normal conditions of light stimulation.
● If your skin is young and fair, you can choose gradient-colored lenses. But whatever color you choose, the fundamental principle should be that it does not affect visual discrimination.
Not all lenses need to be coated
Nowadays, there are all kinds of coated lenses on the market, red, orange, yellow, green, blue and purple, all kinds of color films. Is this film really that amazing?
First of all, coated lenses do have many advantages. For example, the coating of gold, silver and zinc sulfide on the surface of the lenses can selectively reduce the transmission of harmful light in certain wavelengths such as ultraviolet and infrared, thus reducing the damage to the eyes. However, this does not mean that the more layers of lenses are better, but that the choice should be made according to the actual situation.
If you can see clearly and comfortably with ordinary lenses, you don’t need to add a film. If you want to add, resin lenses can be added with anti-reflective film or with hard film; glass lenses are generally added only with anti-reflective film.
The lenses that are currently available on the market are usually treated with a multi-layer film, making them multi-functional. Therefore, it is important to check the detailed description of the lenses when purchasing them.