What is Single Vision Spectacle Lens, what is the difference between Single Vision Lenses and Functi

Monofocal spectacle lenses are commonly referred to as monofocal lenses, that is, lenses with only one optical center, while bifocals have two optical centers.

In refractive correction, the lens that can be corrected to make the vision a visual focal point, that is, a single vision lens.

Single-vision glasses are the most basic lenses, that is, a single focal, looking far and near, there are more varieties of lenses now, multifocal, that is, more functional, so choose according to different needs;

2.Single vision spectacle lens: with single vision distance refers to single vision lens, colloquially speaking, it refers to single vision lens, that is, lenses with only one optical center, including spherical lens, cylindrical lens, and spherical cylindrical lens.

There is only one power on the lens, and the most basic radiation and ultraviolet protection is available, and a single light can also be called a spherical lens, and astigmatism can also be added.

The difference between single vision lenses and functional lenses is that one can effectively prevent and control myopia (functional lenses), and the other is just a simple myopia lens (single vision lenses).

Functional myopia lenses are more useful, and for some adolescents, functional myopia lenses can play a role in relieving eye fatigue, so that the myopia can be deepened.

Functional lenses are different from single-vision lenses, which have only one optical centroid, so the entire lens has only one power. Functional lenses have multiple optical centers, so the power of the edge of the lens is relatively low, so that people's eyes will not be too tired when looking close, and it is more suitable for people who use their eyes for a long time.

How to choose the right glasses for you:

Single vision vs function: Compared with single vision lenses, functional lenses can meet more eye needs, if the eye axis is normal, normal visual function, single vision lenses can be selected; However, if you have presbyopia, abnormal accommodative function, myopia and implicit strabismus, etc., you can consider choosing progressive multifocal lenses.

Lens refractive index: the refractive index reflects the thickness of the lens; Some friends who are worried about the thickness of the glasses can choose lenses with a high refractive index to reduce the thickness of the lenses.

Glass vs resin: Resin lenses have the characteristics of light weight, not easy to break, and light transmittance comparable to glass lenses. Glass lenses are an option for patients with special requirements or heights.

Spherical vs. aspherical: Spherical or aspherical lenses differ in visual quality; There is a certain curvature around the spherical lens, so that the edges of the object may be bent; Aspherical lenses have better image quality.

Single-vision lenses refer to lenses with a degree without astigmatism, anti-fatigue lenses, and are designed to have a progressive, 75-degree lens progressive lens with a lower part of the lens, that is, there is a certain degree of power above and below the lens. Lenses, made of optical materials such as glass or resin, are transparent materials with one or more curved surfaces, and are often assembled with spectacle frames to form glasses after polishing, which are used to correct the user's vision and obtain a clear vision. <

Single-vision lenses refer to lenses with a degree without astigmatism, anti-fatigue lenses, and are designed to have a progressive, 75-degree lens with a progressive lens at the lower part, that is, there is a certain degree above and below the lens. Lenses, made of optical materials such as glass or resin, are transparent materials with one or more curved surfaces, and are often assembled with spectacle frames to form glasses after polishing, which are used to correct the user's vision and obtain a clear vision.

Single vision lenses refer to spectacle lenses that have only one optical power, and are usually used to correct nearsightedness or farsightedness. Compared with multifocal lenses, single vision lenses have only one optical power, so they can only focus on one type of sight distance in the focal length, and cannot correct myopia and farsightedness at the same time. In general, single vision lenses are suitable for people who only need to correct one type of sight distance.

Optical lenses are the use of optical glass.

The definition of the manufacture of lenses, optical glass, is the refractive index.

Glass with specific requirements for optical properties such as dispersion, transmittance, spectral transmittance and light absorption, and uniform optical properties. Glass that can change the direction of light propagation and change the relative spectral distribution of ultraviolet, visible or infrared light. <

Optical lens is a lens made of optical glass, and the definition of optical glass is a glass with uniform optical properties such as dissipation, dispersion, transmittance, spectral transmittance and light absorption in refraction. Glass that can change the direction of light propagation and change the relative spectral distribution of ultraviolet, visible or infrared light. Optical glass in the narrow sense refers to colorless optical glass; Optical glass in a broad sense also includes colored optical glass, laser glass, quartz optical glass, radiation-resistant glass, ultraviolet infrared optical glass, fiber optical glass, acousto-optic glass, magneto-optical glass and photochromic glass.

Optical glass can be used to manufacture lenses, prisms, reflective mirrors and windows in optical instruments. Components made of optical glass are key components in optical instruments.

Optical glass is made of high-purity silicon, boron, sodium, potassium, zinc, lead, magnesium, calcium, barium and other oxides mixed according to a specific formula, in a platinum crucible.

Melt at medium and high temperatures, stir evenly with ultrasonic, and remove bubbles; It is then slowly cooled over a long period of time to avoid internal stress in the glass block.

After cooling, the glass block must be measured by an optical instrument to check whether the purity, transparency, uniformity, refractive index and dispersion rate meet the specifications. The qualified glass blocks are heated and forged to form optical lens blanks.

Monofocal lenses are ordinary eyeglasses.

Monofocal glasses therefore refer to a focal lens, usually we see myopia, farsightedness, presbyopia, etc. are monofocal glasses, a lens has only one luminosity, this is monofocal.

Both monofocal glasses and multifocal glasses are tools for correcting vision, but monofocal glasses can meet basic vision needs, but cannot meet the needs of different distances such as relieving fatigue, controlling luminosity deepening, and looking at the distance, looking far and near. However, multifocal glasses because there are multiple different luminosities on a lens, so the middle-aged and elderly can not only see far after wearing, but also do not need to take off the glasses or wear reading glasses when they have presbyopia, so young and middle-aged people usually look at the computer for a long time will be more tired of their eyes, and they are not easy to get tired after wearing multifocal glasses, and teenagers can effectively control the deepening of eye luminosity when wearing multifocal glasses.

Single-vision lenses refer to lenses with a degree without astigmatism, which are the most common spectacle lenses, which are made of optical materials such as glass or resin, and are transparent materials with one or more curved surfaces, which are often assembled with glasses frames to correct the user's vision and obtain a clear vision.

Single-vision lenses are commonly referred to as monofocal lenses, that is, lenses with only one optical center, which can correct central vision, but do not correct peripheral vision.

With ordinary single vision lenses, when the imaging in the center of the lens just falls on the macular area in the center of the retina, the imaging focus around the retina actually falls behind the retina, which is the so-called peripheral hyperopia defocus. Since the focal spike falls behind the retina, it will induce compensatory elongation of the eye axis, and for every 1 mm increase in the eye axis, the myopia will increase by 300 degrees.

Corresponding to the monofocal lens is the bifocal lens, the bifocal lens is to have two focal points on a pair of lenses, usually the upper part of the lens is a normal power lens, used to see the distance, and the lower part is a lens with a certain power added, used to see the near distance. However, bifocal lenses also have disadvantages, as the power of the upper and lower lenses varies greatly, so it can be uncomfortable for the eyes when looking far and near.

1. Advantages of multifocal glasses: (1) The appearance of the lens is like a single vision lens, and the dividing line of power change cannot be seen. Not only is it beautiful in appearance, but more importantly, it protects the wearer's age privacy, and there is no need to worry about revealing the secret of age due to wearing glasses.

2) Since the change of lens power is gradual, there will be no image jump. Comfortable to wear and easy to adapt. Therefore, it is easy to be accepted.

3) Because the power is gradual, the substitution of the adjustment effect also increases gradually according to the shortening of the visual distance, and there is no adjustment fluctuation, which is not easy to cause visual fatigue.

4) Clear vision can be obtained at all distances in the visual range. A pair of glasses can be used at the same time for long-distance, near-use and intermediate distances. (5) The eyeball is not easy to fatigue, and the external luminosity of the progressive lens can be artificially added to the progressive luminosity, and the upper depth is used to see far, and the shallow power below is used to see near, so that the eyeball is relaxed and over-adjusted.

The ever-changing luminosity of the lens replaces the "adjustment force" that should be enabled, blocking the vicious cycle of adjustment-eye axis elongation, making the eye less susceptible to fatigue and slowing down the progression of myopia.

2. Disadvantages: Wearing progressive multifocal glasses for the first time may occur: slight dizziness, shaky walking, and caution when walking up stairs during exercise.

The sense of space changes, the distance judgment of the object, and the depth perception changes, and the first-time wearer should not drive immediately and do strenuous exercise. When looking close, the eyes need to be turned downward, and the eyes will be slightly uncomfortable. Seeing an object through a blurred area around the lens becomes blurry.

Therefore, when looking at things, the first-time wearer rotates his head more and less eyes, and tries to use the far-reaching, near-use, and medium-distance areas to look at objects.

The difference between multifocal lenses and single-vision lenses is: the focus is not the same, the suitable people are different, and the purpose is different.

First, the focus is different.

1. Multifocal lenses: There are multiple focal points on multifocal lenses, and they are progressive.

2. Single vision lens: There is only one luminosity (focus) on the single vision lens.

Second, the suitable group of people is different.

1. Multifocal lenses: Multifocal lenses are suitable for those who need to correct vision from a distance and a medium distance, such as sports athletes (medium and long-distance projects), outdoor activities, etc.

2. Single vision lens: single vision lens is suitable for indoor work and copywriting workers, but not for long-distance workers.

Third, the purpose is different.

1. Multifocal lenses: The purpose of multifocal lenses is to alleviate the development of myopia in adolescents and relieve visual fatigue in young and middle-aged people.

2. Single vision lens liquid or mega: The purpose of single vision lens is to solve the problem of presbyopia.

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