Researchers 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.

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, University of California Berkeley professor of computer science and vision science.

"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," said Barsky.

Researchers teamed up with colleagues at the Massachusetts Institute of Technology (MIT), to develop their latest prototype of a vision-correcting display.

The setup adds a printed pinhole screen sandwiched between two layers of clear plastic to a display to enhance image sharpness. The tiny pinholes are 75 micrometres each and spaced 390 micrometres apart.

The algorithm 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.

In the experiment, the researchers displayed images that appeared blurred to a camera, which was set to simulate a person who is farsighted. When using the new prototype display, the blurred images appeared sharp through the camera lens.

Lead author Fu-Chung Huang noted the prototype could easily be developed into a thin screen protector, and that continued improvements in eye-tracking technology would make it easier for the displays to adapt to the position of the user's head position.