Digital image processing for pre-compensation of high-order aberrations of the human eye

Human beings rely significantly on their visual capabilities to successfully interact with their environment. In today's technology-based world, one of the most important interaction channels is through computers. Some individuals with severe visual impairments may have difficulty in interacting with computers, even when using traditional means of visual correction (e.g., spectacles, contact lenses). This is, in part, because these correction mechanisms can only compensate for the most regular distortions or aberrations of the image in the eye. This paper proposes an image processing approach that will pre-compensate the images displayed on the computer screen, so as to counter the effect of the eye's aberrations on the image. The characterization of the eye required to perform this customized pre-compensation is the eye's Point Spread Function (PSF). The PSF can now be measured by a new generation of ophthalmic instruments generically called. Wavefront Analyzers.. The characterization provided by these instruments also includes the .higher-order aberration components. and could, therefore, lead to a more comprehensive vision correction than traditional mechanisms. The methods presented here will be explained in terms of their theoretical foundation and illustrated with results from the correction of aberrations introduced by lenses with known and constant PSFs.