Why Do Glasses Take So Long to Make?

After every option is talked through with your new glasses the order is being placed at the manufacturer who cuts and coats the lenses. After you read this article you will know what steps are necessary to complete your glasses and why they take so long to make?

Usually, the time until your glasses are ready for pickup is around a couple of minutes up to two weeks. In some cases, the optical shop already has your ordered lenses in stock. In such a case the time to make can be reduced to a minimum. Because all that needs to be done is take the lenses out of the drawer and perform the following tasks:

  • Trace the shape of your glasses frame
  • Add a block pad to the lenses surface so the lens can behold by a CNC machine
  • The lenses get cut to the right shape by the CNC machine
  • Now the lenses need to be fit into your glasses frame
  • The frame needs to be adjusted
  • After the steps above your glasses need to be check for scratches

All the steps combined above take approximately six minutes. I worked a few years in the workshop of an optical store where approximately 50 glasses per day were being made. You can see the process here in the video below.

When it comes to the lenses in stock there is only one configuration to choose from. Those are usually plastic lenses that have an anti-reflection to them a clean coat and a coating that makes the lenses more durable.

For a lot of people this leads to very satisfying results. But when you are farsighted with a prescription higher than two diopters for example it oftentimes makes sense to order the lenses custom made. Besides the huge variety of options that come with RX is lenses in terms of the coatings, lens designs and tints they simply can be cut to a minimum thickness.

The optical shop sends the data of how the lenses need to be cut to the manufacturer. The manufacturer than calculates which diameter works best for you. With a smaller diameter the lenses get thinner and lighter.

Usually the whole process is automated so when I say the manufacturer decides I mean the software of the manufacture instantly knows what to do.

Then the blank is picked. This is the base material. After this pickup process a CNC machine takes over and the blank gets cut by a CNC machine. Before I already talked about a CNC machine but this time the lens surface will be cut and polished.

After this is done in some case a laser cuts an engraving into the lens. This helps the optician to identify the perfect spots to measure your prescription.

The next step is the coating. Depending on how good the coating is multiple layers will be added to the lens’s surface to get the desired anti-reflective capabilities, the lotus effect, and the more durable lens surface.

Then after quality control, the lenses get packaged and send to the optician where he or she cuts the edges of the lenses to fit them to your chosen frame. This whole process takes the manufacturer approximately four hours up to several days.

I personally would not go with the four-hour option anymore. I tried it a few times but frankly spoken the results were just better when the lenses arrived after a couple of days instead of tomorrow. As exciting as it sounds to produce lenses very fast the quality of the coatings was just not ideal oftentimes.

But What About Higher Prescription? Why They Might Even Take Longer?

In the case of a very high prescription, the stock lenses that are kept don’t usually go up that high. In the part above I described the cutting process. In some cases with extreme lens shapes the whole process needs to be restarted because of a scratch or a faulty coating.

The CNC machines can cut lenses fairly easily in most cases. But when your prescriptions fall outside of the normal range the person checking your job may have to start it multiple times.

In such a case two weeks are oftentimes fast when it comes to very high prescriptions. When we order prescriptions in the 30 diopters range I oftentimes tell my customers the process will take up to 3 weeks.

Good things need a little time and when I see something that is not ideal when it comes to the glasses I as an optician want to have enough buffer to reorder the lenses. With the manufacturers, we trust in this happens seldom.


Depending on if your lenses are in stock or not the time for your glasses to be made will vary a lot. If you order your glasses and you need your glasses fast ask the optician what would accelarate the manufacturing process.

For example, if you order plastic lenses that are fully coated and that is it you can fairly easily get your lenses faster. But if you add a slight tint to the configuration then those lenses need to be custom made and get tinted by hand. This immediately adds a lot of time until your glasses will be ready for pick up. So ask the staff if this is the fastest option.

In a lot of cases, a minor change in the coatings or the tint will make the whole process faster. Just tell them your wishes.

I wish you a great day.

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