Prescription glasses are everywhere. You may even be wearing some right now! It’s not difficult to overlook how these marvels are made, considering their ubiquity. But it turns out, quite a lot goes into each pair of eyeglasses – it’s much more than simply putting a piece of plastic or glass into a frame. Here’s a brief overview on how prescription glasses are made and how far they’ve come.

Edina Eye offers the latest trends in eye wear. For a prescription, call for an appointment today!

Prescription Glasses: A Brief History

The exact origin of eyeglasses is a little blurry. Greek texts describing reading optics and references to “reading stones” have been traced back to the 9th and 10th centuries.

Historic lenses and eye wear. The making of lenses has changed over many years. Materials such as polycarbonate and high index plastics has made for better optics for people. Although there is some debate as to when and where the very first vision aids were created, it’s widely accepted that the first iteration of eyeglasses originated in Pisa, Italy around 1280. The design – which consisted of a metal frame with two glass or crystal stones that was held up to the eyes – wasn’t far off from what we wear today, and it certainly set the stage for what was to come.

Over the next several hundred years, eyeglasses became more commonly exported across Europe and the technology improved as well. This included the invention of bifocals, lenses for astigmatism, spherical point-focus lenses and eventually contact lenses.

Glasses today are almost as much a fashion statement as they are a necessity, as they come in a large variety of shapes, colors and sizes. Despite the successful developments of contact lenses and laser corrective surgery, it’s estimated that 64 percent of American adults who use corrective lenses wear eyeglasses.

Modern Lenses and How They’re Made

Long gone are the days of stone or crystal lenses. Modern prescription glasses are extremely lightweight, durable and much more accessible to the general 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 crafting process starts in an optometrist’s office, where a patient undergoes an eye exam to determine their Making polycarbonate lenses is something Edina Eye can help you with. prescription. Based on the prescription, each lens will be ground, beveled and edged into the shape and size required for improved vision.

An optical prescription includes values such as:

  • Axis – a number between 0 and 180 degrees indicating the orientation of astigmatism
  • Spherical base strength – A negative or positive value measuring nearsightedness or farsightedness
  • Cylinder base strength – A negative or positive value measuring the degree of astigmatism

Lens Blank Crafting

Each finished lens begins as a lens blank – a piece of polycarbonate plastic or glass that’s generally about the size of a Checking measurements for prescription placement is important for lenses and you to see properly. Edina Eye ophthalmologists are experts at this. Call today. circular coaster. One side of the blank comes with a curvature while the other is flat. A technician selects a lens blank with the correct amount of existing curvature so that it corresponds with the patient’s prescription.

Using a lensometer, the blanks are marked at the “optical center,” which refers to the exact point that will be over the patient’s pupil. Then, each lens is affixed with adhesive tape to keep the lens from being scratched during the grinding and blocking processes. After the tape is in place, a blocker is attached using heated lead alloy. This holds the lens in place during the grinding phase. The

Adjusting the armature of the glasses is important for the lens to sit properly on your eyes. Call Edina Eye Clinic for an appointment today!

lens is then placed in the generator, or grinding machine, and the flat back of the lens is ground into the correct shape.

After the lens is correctly curved, it must go through a series of polishing, beveling and sterilization treatments, often performed using a fining machine and several other tools, such as soft sandpaper. The block and tape are removed by hand during this phase.

The final step in the process is edging, which is completed with an edge grinder. This machine grinds each lens into the final, proper shape and places a bevel around the edge so each lens fits snuggly into the frame. After the lenses are dipped in a coat of UV treatment and tint, if desired, they are ready to be placed in the frame and worn by the patient.

Quality Control

To ensure each pair of glasses crafted in the U.S. works as intended, strict guidelines set by the Food and Drug Administration and American National Standards Institute must be followed. Further, the National Optical Association requires all optical laboratories to be licensed and adhere to a variety of quality and safety standards. There are four basic quality assurance steps performed throughout the crafting process:The process of making prescription eye glasses is not an easy or quick thing to do. Precision and expertise is required to make the lens just right for your vision.

  • Checking for scratches, chips and cracks
  • Confirming the prescription is correctly inputted into each machine
  • Verifying the optical center is correctly marked
  • Verifying optics while the lenses are in the lensometer

Need a Pair of Prescription Glasses of Your Own?

From single vision to progressive lenses, Edina Eye Clinic can help you get the glasses you need for your individual eyesight. Call us today! The process of crafting a pair of prescription glasses requires a great deal of precision and expertise – from your eye exam to the moment you place your glasses on your face. If you or someone in your family is in need of prescription eyeglasses, it’s important you work with a professional optometrist so you get the clearest results.

Edina Eye Physicians provides a wealth of comprehensive vision care services, including eye wear. For more information or to schedule an appointment, call (925) 832-8100 or visit us online.