Typical glasses: nearsighted glasses, farsighted glasses or presbyopic glasses, keratoconstrictor lenses, astigmatism lenses, and sunglasses.
Lenses can be divided according to material: resin lenses, glass lenses, and plexiglass.
Lenses are also distinguished between spherical and aspheric lenses
Frames can be divided into two categories according to the material: metal and non-metal; each has its corresponding advantages and disadvantages.
Metal contains pure titanium, beta, titanium alloy, and alloy material. Among them, pure titanium stability is good, not easy to corrosion, not easy to allergy, light texture is currently a relatively strong frame material, but the price is relatively high. β titanium flexibility, adjustable, and rather more cost-effective. Titanium alloy: the frame contains titanium material, high hardness and plasticity, and is a little heavier. Alloy material is more flexible, encounters external force bending, and can quickly recover; relatively cheap but will be heavier.
The non-metallic material includes TR90 and Acetate. TR90 has good elasticity, is not easily deformed and discolored, and is lighter to wear. Acetate is not accessible to allergic and does not easy to lose color, and the texture is better.
ABBE Glasses offers free glasses and a wide range of styles from which you can choose the right one.
The type can be divided into full-rim, half-rim, and rimless glasses.
Full-rim glasses: characterized by intense, easy to shape, and can cover part of the lens thickness
Half-rim glasses: A very thin nylon wire is used as part of the frame edge so that the nylon wire is embedded in the groove, forming a bottomless frame style, relatively light.
Rimless glasses: There is no frame set, and they are relatively lighter, and the form of lenses made by the cutting process can be more varied. However, it is not advisable to wear rimless glasses if the prescription is too high, and the lenses will be relatively thick if the prescription is too high.
When choosing lenses, consider the refractive index; the refractive index is the factor that determines the thickness of a lens, generally speaking, the thinner the lens, the higher the light transmission. That is, the higher the refractive index at the same degree, the thinner the lens, and the higher the refractive index, the higher the price.
But when we buy glasses, we can’t just consider the refractive index because although the refractive index is high, the light transmission is not necessarily good, and we match glasses to see things better. If the light transmission is not good and you can’t see things, then what is the meaning of matching glasses? Generally speaking, for myopia prescription below 300 degrees, choose a 1.56 refractive index; for more than 300 degrees, choose a 1.60, 1.67, or 1.74 refractive indexes is also more appropriate.
Lenses are divided into glass, resin, and PC lenses. Among them, the refractive index of glass lenses is better; that is to say, at the same degree the same refractive index, glass lenses are thinner, but glass lenses are heavier and easy to break, easy to hurt the eyes. On the contrary, resin lenses and PC lenses are better, lighter, impact-resistant, and even UV resistant.
Glass lenses are hard, heavy, wear-resistant, and fragile, but it is because glass glasses are fragile that they are not suitable for rimless glasses. Resin lenses are suitable for rimless glasses because of their lightness and unbreakability. PC lenses have a small specific gravity, high toughness, and high safety. Rimless glasses in the production process and the use of the process need to be good toughness of the lens, that is, not easy to break. This point PC lenses exactly match. If the degree of myopia prescription is not high enough, punching is easier to crack. If the prescription is low, choosing rimless glasses frames is still not recommended; you can try other eyeglasses frames.