Prescription glasses are everywhere. You might even be wearing some right now! Given their ubiquity, it's not hard to ignore how these wonders are made. But it turns out that every pair of glasses contains a lot - it's not just about putting a piece of plastic or glass into the frame. Here's a brief overview of how prescription eyeglasses are made and how they've evolved.

The exact origin of the glasses is a bit murky. Greek texts describing reading optics and references to "reading stones" date back to the 9th and 10th centuries.

Although there is some debate about when and where the earliest vision aids were created, it is generally believed that the first generation of glasses originated in Pisa, Italy, around 1280. The design, which consists of a metal frame and two pieces of glass or crystal stone, is eye-catching - not too far from what we're wearing today, and it certainly sets the stage for what's to come.

Over the next few hundred years, glasses became more common in Europe, and technology improved. This includes the invention of bifocal lenses, astigmatic lenses, spherical point focus lenses, and eventually contact lenses.

Today's glasses are almost as much a fashion statement as they are a necessity, as they come in a wide variety of shapes, colors, and sizes. Despite the success of contact lenses and laser correction surgery, an estimated 64 percent of U.S. adults who use corrective lenses wear glasses.

Gone are the days of stone or crystal lenses. Modern prescription glasses are much lighter, more durable, and more accessible to the public than they were centuries ago, thanks in large part to the gradual shift from glass to polycarbonate lenses in the mid-1900s.

The lens-making process begins in the optometrist's office, where patients undergo an eye exam to determine their prescription. As prescribed, each lens will be ground, beveled, and edged to the shape and size needed to improve vision.

The optical prescription includes the following values:

Axis - a number between 0 and 180 degrees, indicating the direction of the astigmatism

Spherical basal intensity - measures negative or positive values for nearsightedness or farsightedness

Base intensity - a negative or positive measure of the degree of astigmatism

Each finished lens starts with a lens blank - a piece of polycarbonate plastic or glass, usually about the size of a round coaster. One side of the blank is curved and the other side is flat. The technician selects the lens blank with the correct curvature to match the patient's prescription.

Using a lens gauge, the blank is marked at the "optical center," which is the exact point that will be above the patient's pupil. Each lens is then taped to prevent the lens from being scratched during grinding and blocking. After the tape is in place, use a heated lead alloy to attach a blocker. This holds the lens in place during the grinding stage.

The lens is then placed in a generator or grinder to grind the flat back of the lens to the correct shape.

Once the lens is properly bent, it must go through a series of polishing, beveling, and sterilization treatments, usually using a polisher and several other tools, such as soft sandpaper. Blocks and tape are removed manually at this stage.

The final step in the process is edging, which is done using an edging machine. This machine grinds each lens to its final proper shape and places a bevel around the edge so that each lens fits snugly against the frame. After the lenses are dipped in a layer of UV treatment and tinting, they can be placed in a frame and worn by the patient if desired.

Four basic quality assurance steps are performed throughout the production process:

Check for scratches, chips, and cracks

Confirm that the prescription is entered correctly into each machine

Verify that the optical center is correctly marked

Verify optics while the lens is in the lens gauge

The above describes the production process of prescription glasses in detail. If you want to buy glasses, please contact us.

ZOHO is a professional custom eyewear manufacturer with more than 20 years of experience. We mainly deal in lenses, frames, sunglasses, reading glasses, contact lenses and eyeglass accessories, which are in stock and can also be customized by OEM/ODM. ZOHO has reached good cooperation with more than 200 suppliers in Asia. We have served more than 5,000 clients worldwide.