Color blind glasses

This is how glasses are made in a factory

It’s more than just putting a piece of glass in a frame.

If the video player is not working, you can watch the video from this alternative link.
If you’re unlucky enough to need your eyesight corrected, then you’re probably more than familiar with glasses. They come in a huge range of shapes and sizes, but have you ever wondered how they’re actually made?

Let’s find out, shall we?

Source: Interesting engineering

Step 1: Making the frames

The first step in the manufacture of glasses is to manufacture the frames of the corrective lenses. These begin life, for the metal ones at least, as spools of wire.

These coils are first fed into a special machine that bends the wire into loops. The diameter and shape of the loops will vary depending on the final eyewear design, but the basic process is more or less the same.

Loops or metal wire, then cut the main thread from the yarn and collect them ready for the next phase of the production process.

make glasses loops
Source: Interesting engineering

These loops are then welded together to make the edges of the glasses as needed. This done, other special machines are also used to add the bridge and the arms of the glass frames.

For the bridge, the rims are placed on a special mounting frame and human workers weld the arch of the bridge in between. This is a delicate job that requires skilled and experienced workers to carry it out efficiently.

make eyeglass frames
Source: Interesting engineering

Once completed, the frames are collected and moved on to the next phase of production. Here, human workers take each finished frame and give it a good polish using a rotary polishing machine.

The metal is polished and the weld lines are flattened and removed, if necessary. It is judged by eye.

polish glasses
Source: Interesting engineering

Step 2: Finishing the frames

Then batches of frames are placed in a special frame ready for coating. Once ready, each batch of metal eyeglass frames is then dipped in a special hot liquid to add a protective layer to the metal frames.

soak glasses
Source: Interesting engineering

This is for a variety of reasons including the addition of decorative elements such as color etc. specific to the final design of the particular glass frames. This process may also include adding layers of plastic to the metal frame.

This done, the lenses then undergo another round of polishing. In this case, the metal frames are added to a vibrating polishing machine in batches.

vibrate polishing glasses
Source: Interesting engineering

After the vibration polishing is complete, the next step is to assemble the frames. At this factory, this is mostly done by hand with arm hinges inserted into the rims.

The completed rims are then passed to another group of workers who manually attach the arms to the hinges using mechanized screwdrivers.

make eyeglass hinges
Source: Interesting engineering

Once this operation is completed, the frames with arms are exposed to another cycle of cleaning and treatment. Once this is complete, the frame is then spun through a series of holders to dry evenly.

Another round of polishing then follows to refine the frames and ensure they meet the factory’s rigorous quality standards. Other parts are then added to the frames like nose mounts etc as needed.

Step 3: Making the lenses

Now that the essential parts of the frames are complete, the next step is to finish the most important part of the glasses: the lenses. These start out as discs of glass with specified optical properties.

The lenses are then placed in special grinding machines to cut them into the size and shape needed to make the base lenses for eyewear. These are not founded to meet prescriptions, but rather provide sample lenses for generic frames.

make eyeglass lenses
Source: Interesting engineering

During lens manufacturing, the frames are exposed to further processing. At some point in the process, the mark is added to the frames if necessary.

In this case, the customer’s brand is added to the temples of the glasses using a special press. This automatically buffers the areas in question as needed.

manufacture of glasses
Source: Interesting engineering

Step 4: Inserting the lenses

With that done, the next and arguably most important step is to fit the lenses into the frames. This, like other delicate parts of the process, is also done by hand.

Human workers add a rubber band around the eye lens holes in the frames, then gently push the glass lenses into place in the frames.

make glasses adapted to the glasses
Source: Interesting engineering

This is done with great care to avoid damage to lenses and frames. Eventually, the lenses will fit snugly into the frames as needed.

The next step is to bend the back of the arms using a specialized press to give the arms their dogleg shape.

Once this is done, the glasses then move on to the final stage of production – final quality checks. Here, quality control staff perform a visual check on each pair of glasses and then test each for balance.

Minor adjustments are made to the angle of the arms as needed before each pair receives another final hand polish.

msking glasses polishing
Source: Interesting engineering

This done, the glasses are then packed and prepared for shipment.

If you enjoyed this behind-the-scenes look at how eyewear is made, you might like to watch another industrial process in progress. How about, for example, seeing how the socks are made?