Eye opener

Making contact lenses is one of the ultimate high-precision tasks. Tolerances are necessarily tight — any deviation, and the lens may not provide the required correction and could irritate the eye, making it worse than useless. But it’s also a high-volume operation, and manufacturers want to make the largest number of lenses, from the smallest amount of material, as fast as possible.

The UK-based Clearlab facility in Plymouth is now operating a production process which, it claims, is the world’s first fully-automated contact lens manufacturing system. Developed over three years along with system integrator Barr & Paatz, the entire system occupies just eight square metres, yet produces over 24 million daily disposable contact lenses, every year, with considerable savings in materials consumption.

Contact lenses are not easy to make, explained Clearlab’s technical support manager Jim Curtis. ‘You can’t mould lenses in a press,’ he said, ‘because the polymers they’re made of act like glue — they stick to the tooling and gum everything up.’