On-Screen Deconvolution to Facilitate Computer Access for Users with Visual Impairments Involving Higher-Order Wavefront Aberrations

通过图形用户界面与计算机的成功交互隐含地要求对计算机屏幕上显示的图像具有不失真的感知。对于那些有严重和不规则视力限制的人来说，这是一个问题，这些人无法通过眼镜或隐形眼镜等传统机制来矫正。在这个项目中，PI将探索让计算机生成修改显示的可能性，以纠正诸如圆锥角膜、透明边缘变性、Terrien边缘变性以及相关的折射障碍等疾病，这些疾病扭曲了眼睛以不对称和不规则的方式感知的图像。由于需要在眼睛波前像差（WA）函数的泽尼克多项式近似中包含高阶（即2）项，从而捕获了由这些条件引入的畸变的不规则性，波前像差（WA）函数表示通过眼睛的光学部件（角膜，晶状体）的图像畸变。图像处理和验光的最新进展，以及实时应用中不断增加的计算能力的持续承诺，使我们有可能设想这样一种计算机系统：给定用户视觉能力的适当特征，将以一种互补的方式产生与他/她的视觉限制相匹配的显示，从而克服用户的视觉问题。此外，能够准确表征一个人的WA的仪器现在已经商业化。PI和他的团队将使用从一个人的WA中获得的点扩散函数（PSF）来预补偿（通过反卷积）显示在计算机屏幕上的图像，以便被考虑PSF的个人感知到它们没有扭曲。更广泛的影响：该项目将导致新的辅助技术的设计，这反过来可能会导致工具，造福广大人口。由于将有大量学生参与该项目，而且PI所在机构是全国为数不多的少数民族机构之一，拥有通过博士水平的综合课程，因此预计将对教育产生重大影响。反褶积工作在技术和社会层面都具有广泛影响的潜力，因为它构成了一种通过数字而不是光学手段来补偿视觉矫正目的的图像的新方法，并且考虑到在传统解决方案中被忽视的高阶视觉障碍可能影响多达700万患有过度不规则屈光不正的美国人。

Successful interaction with a computer through a graphical user interface implicitly requires the undistorted perception of the images displayed on the computer screen. This is a problem for individuals with severe and irregular visual limitations that cannot be corrected through traditional mechanisms such as eyeglasses or contact lenses. In this project the PI will explore the possibility of having the computer generate modified displays to correct conditions such as keratoconus, pellucid marginal degeneration, Terrien's marginal degeneration, and related refraction disorders that distort the images perceived by the eye in asymmetrical and irregular ways. The irregularity of the distortion introduced by these conditions is captured by the need to include higher-order (i.e., 2) terms in the Zernike polynomial approximation of the eye's wavefront aberration (WA) function, which represents the distortion of images through the optical components of the eye (cornea, lens). Recent advances in image processing and optometry, as well as the continued promise of increasing computing power for real-time applications, make it possible to envision a computer system that, given the proper characterization of the visual capabilities of its user, will generate a display that matches his/her vision limitations in a complementary way, thus overcoming the user's vision problem. Furthermore, instruments capable of accurately characterizing a person's WA are now commercially available. The PI and his team will use the point-spread function (PSF), obtained from a person's WA, to pre-compensate (by deconvolution) the images shown on the computer screen, so that they are perceived undistorted by the individual whose PSF is considered.Broader Impacts: This project will lead to the design of novel assistive technologies, which in turn may well lead to tools that benefit the population at large. A substantial impact on education is also to be expected, due to the large number of students who will participate in the project and in light of the fact that the PI's institution is one of the few minority institutions in the nation with comprehensive programs through the PhD level. The deconvolution work has the potential for broad impact in both technical and societal dimensions, in that it constitutes a novel approach to compensation of images for visual correction purposes via digital rather than optical means, and in consideration of estimates that higher-order visual impairment neglected in traditional solutions may affect as many as 7,000,000 Americans who have excessively irregular refractive errors.