The recently launched James Webb Space Telescope (JWST) is set to help rewrite our understanding of the cosmos. Already, astronomers have looked further back into the early universe than ever before — and crucial to the telescope capturing light from over 13 billion years ago are its massive mirrors.
The primary mirror, with its iconic hexagonal shape, is more than two stories in diameter and consists of 18 separate segments. All of these segments must be perfectly smooth, flat and scratch-free so as to provide a flawless image of distant astronomical objects.
Now these mirrors, developed over a decades-long effort by NASA, are helping eye surgeons improve the vision of millions of people by enhancing the accuracy of laser-assisted (LASIK) eye surgery.
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James Webb Mirror Tech
The construction of the JWST mirror segments involved rigorous measuring, grinding, polishing and testing — one of the most time-consuming aspects in the construction of JWST.
“Each mirror is measured independently, changes its shape as it cools, and changes its shape in 0-gravity," says Lee Feinberg, optical telescope element manager for Webb at NASA’s Goddard Space Flight Centre. “All of that needs to be accounted for as you measure mirrors independently so they work in unison properly.”
Scanning Shack Hartmann Sensor
In the early 2000s, the Albuquerque-based company WaveFront Sciences worked with NASA to help develop a system to measure variations in Webb’s mirrors as they were being ground and polished to extremely specific configurations.
“It’s called a Scanning Shack Hartmann sensor and it allows you to measure surfaces with very high resolution,” Feinberg says. “This was helpful in measuring edges of mirrors but is also useful in measuring eyes.”
Complete Ophthalmic Analysis System
The technology, which uses algorithms to detect deviations in the JWST mirrors, was eventually incorporated by WaveFront Sciences into a commercial product capable of diagnosing specific eye conditions by mapping the eye. They called it the Complete Ophthalmic Analysis System.
Tech developed for space exploration has a long history of being re-incorporated into other applications that have proven extremely useful for people back on Earth. In fact, NASA keeps track of these spinoff products, as they’re important reminders of the broader benefits that space exploration can have on society.
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JWST Mirror and Laser Eye Surgery
WaveFront’s system was bought and sold several times before it was acquired by Johnson & Johnson in 2017, who then incorporated it into its iDesign Refractive Studio — a unique tool that takes precise eye measurements to help map imperfections in visual pathways and cornea curvature.
In eyes with regular vision, the cornea refracts incoming light precisely onto the retina at the back of the eye. However, in nearsighted or farsighted people, the light is bent incorrectly, resulting in blurred vision.
Corneal Curvature
During LASIK surgery, a specially designed laser is used to alter the curvature of the cornea. Originally, this was based on the limited information of a patient’s eyeglasses prescription test.
But guided by the tech that helps match mirror curvatures within the JWST, the surgery can now draw on data involving more than 1,200 measurements of an individual's eye — providing a safer, more accurate eye correction.
The technology gained approval from the U.S. FDA in 2018. So far, it’s been rolled out in 47 countries and has assisted in over 18 million successful LASIK eye surgeries worldwide, according to Johnson & Johnson.
Read More: Why More People Are Becoming Nearsighted
