Imagine if computer screens, rather than the people using them, had glasses. This might sound crazy, but thanks to technology being developed by UC Berkeley computer and vision scientists, it might not be too far away. The researchers are currently in the process of developing computer algorithms to make up for somebody with visual impairment, creating vision-correcting displays that help users see text and images clearly without wearing eyeglasses or contact lenses. This technology could potentially help the countless people currently in need of corrective lenses to use their smartphones, tablets and computers. One common problem this technology could help is presbyopia, a type of farsightedness in which the ability to focus on nearby objects is diminished over time as the eyes’ lenses lose elasticity.
More importantly, these displays could eventually aid people with more complex visual problems, which can’t be corrected by eyeglasses. In this day and age, displays are everywhere, and interacting with displays is often taken for granted. People with higher order aberrations tend to have irregularities in the shape of the cornea, making it difficult to have a contact lense that will fit. In some instances, this could be a barrier to holding certain jobs. Such research could dramatically improve the lives of such people. UC Berkeley researchers teamed up with colleagues from MIT to develop the latest 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. These tiny pinholes are 75 micrometers each and spaced about 390 micrometers apart. The research team will be presenting this computational light field display on August 12 at the International Conference and Exhibition on Computer Graphics and Interactive Techniques, or SIGGRAPH, in Vancouver.
What makes this project so interesting is that it uses computation instead of optics to correct vision. The algorithm that they use works by adjusting the intensity of each direction of light that emanates from a single pixel in an image based on a user’s specific visual impairment. In a process known as deconvolution, the light passes through the pinhole array in such a way that the user will see a sharper image. In the experiment, researchers displayed images that appeared blurred to a camera, which was set to simulate a farsighted person. When using the new prototype display, the blurred images appeared sharp through the camera lens. This approach improves upon earlier versions of vision-correcting displays, which resulted in low-contrast images. The new display combines light field display optics with novel algorithms. This research prototype could easily be developed into a thin screen protector, and continued improvements in eye-tracking technology could make it easier for displays to adapt to the position of the user’s head position.
