Month: April 2026

Progressive Multi-Focal Lenses
What are the obvious advantages of progressive lenses?
1.Continuous vision from far to near, clear at distance, intermediate and near ranges.
2.Aesthetic appearance with no visible dividing line.
3.No image jump.
4.Comfortable wearing experience, avoiding the trouble of frequently changing glasses.

Types of Lenses
-Suitable Users for Multi-Focal Lenses:
-Presbyopic people, especially early presbyopes.
-Those dissatisfied with wearing two pairs of glasses.
-Those dissatisfied with traditional bifocal lenses.
-Juvenile myopia patients.(Focus on lenses for slowing myopia progression in teenagers.

By occupation:People with frequent vision shifts; teachers (during lectures); supervisors (during meetings); card players, etc.
Unsuitable Users for Multi-Focal Lenses:
People with cervical spondylosis or migraine;Users with frequent reversed viewing distances, such as:high-altitude workers, people who often look up or sideways at close range (dentists, electrical maintenance workers), pilots, water & electricity workers, operators of large instruments, etc.

Notes for Adaptation:
Relatively long adaptation period;Adjust vision by turning the head;Pay attention to the distribution of visual zones.

Colored Lenses
Colored lenses are resin lenses dyed after substrate production, then hardened and coated.They enhance the fashion sense of the wearer.

PC Lenses
PC lenses are optical lenses made of polycarbonate, produced as thermoplastic resin lenses, while ordinary resin lenses are thermosetting

resin lenses.
Advantages: Ultra-high impact resistance, ultra-light weight;especially suitable for half-rim and rimless frames;environmentally friendly;currently the safest lenses in the world.
Disadvantages:Relatively low surface hardness;require special grinding wheels and methods for processing.

As a professional eyewear supplier, we are specialize in acetate eyewear and metal eyewear and buffalo horn eyewear.

Resin is a hydrocarbon secretion from various plants, especially conifers. It is valued for its unique chemical structure and its use in latex paints and adhesives. As a mixture of many macromolecular compounds, it has different melting points.

Resin can be divided into natural resin and synthetic resin. There are a great many types of resin, widely used in light and heavy industries, and commonly seen in daily life — such as plastics, resin eyeglass lenses, coatings, etc. Resin lenses are optical lenses made from resin through chemical synthesis, processing and polishing.
Features

A. Low density Due to gaps between molecular chains, fewer molecules per unit volume result in low specific gravity and light weight — only about 1/3 to 1/2 the weight of glass lenses.
B. Moderate refractive indexCommon CR39 (allyl diglycol carbonate) has a refractive index of 1.497–1.504.On the market, common resin lenses include aspheric, ultrathin, hardened and coated lenses with a refractive index of 1.67.Many manufacturers now offer 1.74 highindex resin lenses.

C.Surface hardness Lower than glass, so they are easily scratched by hard objects.They require hardening with silica, but still cannot reach the hardness of glass.Wearers must take good care of the lenses.

D.Good elasticity Organic molecular chains allow displacement, making resin lenses about 23–28 times more impactresistant than glass.Europe, the US and Japan prohibit children under 16 from wearing glass lenses.

E. Auxiliary functions Can be treated to provide protection against harmful rays, photochromic effects, and more.
F. Processability Excellent. Suitable for fullrim, halfrim and rimless frames.Permeable dyeing is available for custom colors.
G. Chemical resistance As an organic compound, resin lenses must not be used in acidic or alkaline environments.
H. Thermal properties Do not use above 60°C, as the antireflective coating may crack or peel off.
I. PriceVaries by quality, function, brand and grade.
J. Lens thickness design According to U.S. FDA standards, the minimum center thickness can be 0.6 mm, but strength decreases accordingly.For safety, manufacturers in Europe, the US and Japan generally set the center thickness to at least 1.0 mm for prescriptions over ±1.00 D.

Advantages and Disadvantages
Resin lenses are optical lenses made of resin. Compared with glass lenses, they have unique advantages:

Light weight
Resin: 0.83–1.5 g/cm³Optical glass: 2.27–5.95 g/cm³

High impact resistance
Impact strength: 8–10 kg/cm², several times that of glass.Not easily broken, safe and durable.

Good light transmittance
Similar to glass in the visible light range;Slightly higher in the infrared range;In the ultraviolet range, transmittance drops below 0.4 μm, and almost all light below 0.3 μm is absorbed.

Low cost
After making one precision mold, lenses can be massproduced by injection molding, saving time and cost.

Meet special needs
Aspheric lenses are easy to produce with resin, but difficult with glass.
Disadvantages:
Lower surface wear resistance and chemical resistance than glass
Easier to scratch
Higher water absorption These can be improved by coating.
The main drawback is a high thermal expansion coefficient, low thermal conductivity and low softening temperature, making lenses prone to deformation and degraded optical performance.

As a professional eyewear supplier, we are specialize in acetate eyewear and metal eyewear and buffalo horn eyewear.

For a pair of eyeglasses, the quality of the lenses directly affects vision correction effect and wearing comfort. After years of development and technological innovation, eyeglass lenses have evolved into various materials and functions. So how do these lenses perform, and what are their advantages and disadvantages? Before choosing glasses, we need to learn about lenses in detail.
Glass Lenses

Glass was the earliest and most common material for eyeglass lenses.It features high hardness, resistance to deformation and scratching.During production, other substances can be added to adjust the refractive index for ideal optical performance.
Advantages:High material stability, good light transmittance, effective UV protection, and certain light absorption capacity.
Disadvantages:Fragile and relatively heavy, causing many concerns during wear;large chromatic aberration, which may reduce peripheral vision.
With technological advancement, glass lenses are gradually replaced by new materials.Due to obvious shortcomings in comfort, they are fading out of the market.

Acrylic Lenses
Acrylic lenses, commonly known as organic glass, are plastic lenses developed to replace glass.They are lightweight, low-cost, and easy to manufacture and process.
Advantages:Shatter-resistant, without sharp fragments when broken;suitable for secondary processing and widely used.They serve not only as optical lenses but also in instrument parts, automotive lights, transparent tubes, and even mobile phone and TV screens.
Disadvantages:Easily deformed by heat and poor wear resistance.Thus, they are mostly used for industrial safety goggles.

PC Lenses
PC lenses, also called space lenses or cosmic lenses, are a type of thermosetting material.They are extremely lightweight yet highly tough, and are often used in bulletproof glass.
Advantages:Strong UV resistance, not easy to discolor,impact resistance far superior to other lens materials.
Disadvantages:Poor wear resistance and require coating;the relatively soft material tends to deform under pressure,so they are not suitable for plastic frames or rimless frames.

Resin Lenses
PC lenses are actually a type of resin lens, but differ in processing from standard ophthalmic resin lenses on the market.As the name suggests, resin comes from plant secretions. It is valued for its special chemical structure and uses in latex paints and adhesives, and is widely applied in both light and heavy industries.
Advantages:Lightweight and impact-resistant, just like PC lenses.With UV-resistant elements added, they provide excellent UV absorption.
Disadvantages:Also poor in wear resistance and easy to scratch,with relatively low light refractive index.

As a professional eyewear supplier, we are specialize in acetate eyewear and metal eyewear and buffalo horn eyewear.

Which Lenses Are Best for High Myopia?
When selecting lenses for high myopia, patients should consider not only the cosmetic appearance after wearing glasses but also the protective benefits for ocular health. To determine which lenses are most suitable, it is important to understand the optical characteristics associated with high myopia.

The selection of lenses for high myopia should be evaluated from the following aspects:

1. Choose Lenses with a Refractive Index Above 1.61 Whenever Possible
The refractive index refers to the lens material’s ability to bend light and is the primary parameter determining lens thickness. Currently, the refractive index of most resin (plastic) lenses on the market ranges from 1.49 to 1.74. A higher refractive index results in a thinner lens. Generally, lenses with a refractive index of 1.60 or higher are classified as high-index or ultra-thin lenses.

For individuals with high myopia, lenses with a refractive index above 1.60 are strongly recommended. In addition, high-index glass lenses with refractive indices of 1.80 or 1.90 can be an alternative option, as they may be thinner than resin lenses. However, the production of such high-index glass lenses has become limited in recent years and often requires custom manufacturing, making them relatively expensive.
It should also be noted that resin lenses are commonly paired with semi-rimless or rimless frames for a modern and stylish appearance. However, for patients with high myopia, rimless frames are generally not recommended, as the exposed lens edge can make thick lenses appear even more noticeable.

2. Avoid Glass Lenses Whenever Possible
Glass lenses once dominated the optical frame market, but their disadvantages have become increasingly apparent. These include fragility, safety risks due to breakage, heavier weight, and the tendency to create pressure marks on the nose or ears. Such drawbacks can be particularly problematic for children and adolescents, who often find them uncomfortable.

With advancements in optical materials, resin lenses (including polycarbonate lenses) have emerged as a major innovation in ophthalmic optics. These lenses are lightweight, impact-resistant, safer against breakage, heat-resistant, and generally more comfortable for daily wear. As resin lenses became widely adopted, glass lenses gradually declined in popularity and often remain comparatively expensive.

For young patients with high myopia, resin lenses are generally considered the safer and more practical choice.

3. RGP Lenses: A More Ideal Option for Some Patients
Rigid Gas Permeable (RGP) lenses are high oxygen-permeable rigid contact lenses. For patients with myopia greater than −6.00 diopters who prefer not to wear spectacles, RGP lenses can be an excellent alternative.

Compared with conventional spectacle correction, RGP lenses typically provide sharper retinal image quality, a wider visual field, improved visual performance, and greater freedom from the physical constraints of frames.

For adolescent patients, RGP lenses may also help slow the progression of myopia and can be effective in correcting high astigmatism or irregular astigmatism.

As a professional eyewear supplier, we are specialize in acetate eyewear and metal eyewear and buffalo horn eyewear.