While you may not think there is much that goes into making a pair of prescription eyeglasses, the crafting process is more complex than you’d imagine. Modern glasses are customized to the wearer’s needs and are capable of being able to accommodate a wide variety of prescription needs. If you are curious about the process used to design eyeglasses or you are trying to better understand how to choose glasses that best fit your style and lifestyle, this guide explains how prescription glasses are manufactured.
The components of prescription eyeglasses
Understanding the different parts of eyeglasses can help you choose a pair that is the most comfortable, stylish and functional for your needs. While the main components of every pair of Glasses include the frame and the lenses.
Frames
Eyeglass frames serve the main function of holding the lens in place and staying secure on the wearer's hand. The front section of the frame includes the rims which surround and hold each lens. A bridge piece connects both lenses to each other and the end is on each outer section of the rims allowing the front of the frame to be attached to the arms and temples with hinges.
Frame material
There are many different types of material used to make the frames of eyeglasses, which vary in durability, flexibility, also wood.
Several of the most widely used metal frame types include:
- Nylon: durable, lightweight plastic frame material often used for safety glasses or sports frames.
- Aluminum: A popular metal used for its minimal weight and anti-corrosion properties.
- Titanium: an alternative to aluminum, Titanium glasses are also lightweight, resistant to corrosion and flexible.
- Stainless steel: these glasses are made from a combination of metals including Manganese chromium and Nickel. They are an affordable option for metal frames while they are also durable and lightweight. However, some people have an allergy to nickel and chromates.
- Cellulose acetate: affordable and customisable acetate glasses are made from plant-based hypoallergenic plastic. This material can be made in almost any color combination with varying levels of transparency and finishes
Frame Style
Frames are in many different shapes and style, which are designed to meet a variety of taste and complement different phase shapes.
- Rectangular
- Oval
- Round
- Square
- Cat eye
- Browline
- Aviator and etc.
Lenses
Eyeglass lenses are designed to fit the size and shape of the frame they come with. While lenses were first made out of glass, they are now for less often. Instead, plastic lenses are most widely used as they are less likely to break and cause eye injury.
Columbia resin-39, CR-39 is the most common affordable material used for eyeglasses lenses.
High-index plastic lenses are the thinner, lighter option that has come out in more popular demand for high prescription power.
Polycarbonate lenses are incredibly strong, scratch-resistant and UV resistance. The same material is used for military-grade helmet visors and sports glasses.
Manufacturing process
The first step when making a pair of eyeglasses is to make the frame. While the process varies depending on the material used, die-cutting is a common way frames are manufactured of a certain style is design. A variety of steps are taken to cut and smooth the material into the final product including riveting, curving and polishing.
When making lenses, both human interaction and machinery are used to ensure precision and quality. The lenses must first be measured and shaped to match the frame. A block of plastic is selected and cut to fit this measurement. For glasses that require prescription lenses, this information is entered into a computer system which is used to carve and put the lenses to the appropriate thickness to accommodate the prescription. The lenses are then polished, engraved and inspected to ensure they meet quality expectations. Next, any tint or putting is applied before the lenses are heated or chemically treated to easily insert them into a frame.