Vision-correcting display lets users see clearly without eyeglasses

University of California, Berkeley (UC Berkeley) computer and vision scientists are developing computer algorithms to compensate for an individual's visual impairment, and creating vision-correcting displays that enable users to see text and images clearly without wearing eyeglasses or contact lenses. The technology could potentially help hundreds of millions of people who currently need corrective lenses to use their smartphones, tablets, and computers.

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More importantly, the displays could one day aid people with more complex visual problems, known as high order aberrations, which cannot be corrected by eyeglasses, said Brian Barsky, UC Berkeley professor of computer science and vision science, and affiliate professor of optometry. "We now live in a world where displays are ubiquitous, and being able to interact with displays is taken for granted," said Barsky, who is leading this project. "People with higher order aberrations often have irregularities in the shape of the cornea, and this irregular shape makes it very difficult to have a contact lens that will fit. In some cases, this can be a barrier to holding certain jobs because many workers need to look at a screen as part of their work. This research could transform their lives, and I am passionate about that potential."

The embedded video explains the display in more detail:

The UC Berkeley researchers teamed up with Gordon Wetzstein and Ramesh Raskar, colleagues at the Massachusetts Institute of Technology, to develop their latest computational light field display prototype of a vision-correcting display. The setup adds a printed pinhole screen sandwiched between two layers of clear plastic to an iPod display to enhance image sharpness. The tiny pinholes are 75 micrometers each and spaced 390 micrometers apart.

"The significance of this project is that, instead of relying on optics to correct your vision, we use computation," said lead author Fu-Chung Huang, who worked on this project as part of his computer science Ph.D. dissertation at UC Berkeley under the supervision of Barsky and Austin Roorda, professor of vision science and optometry. "This is a very different class of correction, and it is non-intrusive."

The algorithm, which was developed at UC Berkeley, works by adjusting the intensity of each direction of light that emanates from a single pixel in an image based upon a user’s specific visual impairment. In a process called deconvolution, the light passes through the pinhole array in such a way that the user will perceive a sharp image.

"Our technique distorts the image such that, when the intended user looks at the screen, the image will appear sharp to that particular viewer," said Barsky. "But if someone else were to look at the image, it would look bad."

The National Science Foundation helped support this work.

SOURCE: UC Berkeley; http://newscenter.berkeley.edu/2014/07/29/vision-correcting-displays/