Ophthalmic Lenses

Traditional subtractive manufacturing has been used since the ancient Egyptians. Today the process used for making ophthalmic lenses has been improved significantly. The fundamental principle for manufacturing an ophthalmic lens has however remained the same.

To manufacture an ophthalmic lens in legacy processes, a lens blank is manufactured in a large manufacturing plant.The blank is then shipped to the ophthalmic lab where it is stocked until required. When a certain lens prescription is prescribed for a patient the appropriate blank is selected from inventory and the finishing process starts. Excess materials are cut away to create the final shape of the part and the resulting lens is polished to obtain a smooth surface. The process requires many manual handling steps and more than 10 machine processing steps.

Legacy Ophthalmic Lens Manufacturing Process

Around 80% of used materials are wasted in the cutting (grinding) process. Some of the used material in subtractive manufacturing can be re-used, like for example the heavy metal block that holds the lens during processing in the grinder and polisher. Subtractive manufacturing results in stockpiles of inventory and low yield. On top of that, the produced waste is not really contributing to a more sustainable future.

Additive manufacturing

The way of the future for manufacturing ophthalmic lenses is 3D printing technology which is a development that has come to maturity in very recent times. It has taken manufacturing to a new level in many industries by combining unlimited customization with large volumes when required. Where traditional manufacturing technology is focused on large volumes of identical products, 3D printing allows individual products, in volume.

Meanwhile, 3D printing has disrupted many industries by removing the requirements for identical products and allowing customization to individual needs. It has replaced or at least complemented conventional processing technology and has removed critical bottle-necks in fabrication.
Currently, many different materials can be 3D printed for applications in automotive, aerospace or even spectacle frames. The one elusive application has been optics, because of the requirements in transparency, surface smoothness, and accuracy.

In contrast to subtractive manufacturing technologies, a material is added to create a lens. 3D printing reduces industry expenses by combining efficiency and flexibility in the production flow. There is no need for stocking blanks, stock picking, blocking, taping, grinding, polishing, marking, de-blocking and de-taping. Multiple steps of traditional subtractive manufacturing technology can now be replaced with a single step: 3D printing of the ophthalmic lens.

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