Myopia lens selection method and precautions for eyeglasses
Nowadays, many friends wear myopia glasses, and many of them are more expensive, but do you know how to choose the right glasses for you?
The first thing is to do optometry. This is necessary. Let a professional optometrist use a computerized instrument to perform the test, and then review it with an eye chart to determine your accuracy. If there is astigmatism, you must add it.
Then I choose the lens according to my own power.
If your degree is not very high, below 400 degrees, this is generally a resin with a refractive index of 1.56 plus a radiation-proof lens.
If your power is slightly higher, below -600 degrees, this lens with an aspherical lens with a refractive index of 1.56 is better, and this lens has better imaging , The surface of the lens is relatively flat, not prone to aberration, and the vision is clearer.
If your degree is above 800 degrees, it is best to match a refractive index of 1.67 or 1.74. This kind of lens is thinner and will be lighter after wearing it. A lot, but also a lot more beautiful. There is also a slightly smaller frame selection, so that the effect is better.
Lenses are very important to our eyes. We must choose the lenses that suit ourselves. The health of the eyes is very important.
The first step: Optometry is the prerequisite for good glasses
Most people take this issue seriously, know Go to an optician with a good reputation or a good reputation for optical lenses. The purpose of optometry has two main aspects: one is to check whether the decrease in vision is due to refractive error (nearsightedness, hyperopia or astigmatism) or eye disease; the other is to determine the degree of refractive error. For the first optometry of children, it is best to go to the hospital and undergo dilated optometry after examination by an ophthalmologist. The purpose of mydriatic refraction is to eliminate the possibility of pseudomyopia and to relieve muscle spasm.
The second step: the choice of spectacle frame is very knowledgeable
Spectacle frame material: Spectacle frame material should be light, Tough, firm, durable, not easily deformed, non-irritating to the skin, and not easily corroded by skin secretions. At present, the most common ones in the market are: metal spectacle frames and sheet spectacle frames
type of spectacle frame:
focus lens (1) Full-frame spectacle frames, because the edges of the lenses are thicker, which can block the thickness of the edges, so it is suitable for highly myopic people. You can also choose a frame with a smaller frame.
(2) Half-rim spectacle frames are lighter due to the lack of the lower frame, and the lower frame is fixed by drawing. Therefore, those with medium and high astigmatism should not choose rimless spectacle frames .
(3) Rimless spectacle frames have relatively poor stability, and the lenses are easy to loose or rotate, and the frames need to be adjusted regularly.
(4) Folding spectacle frames, this type of spectacle frame is generally used for reading glasses.
Step 3: Pay attention to lens selection
Lenses are generally divided into glass lenses, resin lenses and PC lenses; from For safety considerations, it is best for children to choose resin lenses or aspherical PC lenses, for high myopia patients, for glass lenses, and for adults to choose suitable lenses according to personal preferences and economic conditions. At present, with the development of science and technology, resin lenses are more and more favored by most customers for their non-breakable, light weight and good UV protection effect. In addition, some customers feel that the same form of frames is sold cheaply in some places and expensive in other places? This is because consumers often pay attention to the appearance, but in fact the inner quality is very different, although the appearance is not at first glance. However, the material and processing technology of the frames are very different. The materials and rare metal coatings of good frames are not comparable to cheap frames. This difference in quality can only be used for a period of time. It will be reflected after time.