The classification of the three major materials
Glass lenses
In the early days, the main material for lenses was optical glass. This was mainly because optical glass lenses have high light transmittance, good clarity, and relatively mature and simple manufacturing processes. However, the biggest problem with glass lenses is their safety. They have poor impact resistance and are very easy to break. Additionally, they are heavy and uncomfortable to wear, so their current market application is relatively limited.
Resin lenses
Resin lenses are optical lenses made from resin as the raw material, processed and synthesized through precise chemical processes and polishing. Currently, the most widely used material for lenses is resin. Resin lenses are lighter in weight compared to optical glass lenses and have stronger impact resistance than glass lenses, making them less likely to break and thus safer to use. In terms of price, resin lenses are also more affordable. However, resin lenses have poor scratch resistance, oxidize quickly, and are more prone to surface scratches.
PC lenses
PC lenses are lenses made from polycarbonate (thermoplastic material) that are formed by heating. This material originated from space program research and is also known as space lenses or cosmic lenses. Because PC resin is a high-performance thermoplastic material, it is suitable for making eyeglass lenses. PC lenses have excellent impact resistance, almost never shattering, and are very safe to use. In terms of weight, they are lighter than resin lenses. However, PC lenses can be difficult to process, making them relatively expensive.
The Suitable Materials for the Elderly
For elderly individuals experiencing presbyopia, it is recommended to choose glass lenses or resin lenses. Presbyopia typically requires low-power reading glasses, so the weight of the lenses is not a significant concern. Additionally, elderly individuals are generally less active, making glass lenses or extra-hard resin lenses more scratch-resistant, while also ensuring long-lasting optical performance.
The Suitable Materials for Adults
Resin lenses are suitable for middle-aged and young adults. Resin lenses offer a wide range of options, including differentiation based on refractive index, functionality, and focal points, thus meeting the diverse needs of different groups.
The Suitable Material for Children and Adolescents
When choosing glasses for children, parents are advised to select lenses made of PC or Trivex materials. Compared to other types of lenses, these materials are not only lightweight but also offer better impact resistance and higher safety. Additionally, PC and Trivex lenses can protect the eyes from harmful UV rays.
These lenses are extremely tough and not easily broken, thus they are referred to as safety lenses. Weighing only 2 grams per cubic centimeter, they are currently the lightest material used for lenses. It is not suitable to use glass lenses for children's glasses, as children are active and glass lenses are prone to breakage, which could potentially harm the eyes.
In Conclusion
The product characteristics of lenses made from different materials are significantly different. Glass lenses are heavy and have a low safety factor, but they are scratch-resistant and have a long period of use, making them suitable for elderly people with low levels of physical activity and mild presbyopia. Resin lenses come in a wide variety and offer comprehensive functionality, making them suitable for the various study and work needs of middle-aged and young people. When it comes to children's eyeglasses, high safety and lightness are required, making PC lenses a better choice.
There is no best material, only an unchanging awareness of eye health. When choosing lenses made of different materials, we must consider from the perspective of the consumer, keeping in mind the three principles of eyeglass fitting: comfort, durability, and stability.
Post time: Jan-08-2024