Most prior research into adaptive user interfaces primarily focuses on facilitating consistent user experiences across devices and pays much less attention to facilitating universal access for diverse end users. We address this shortcoming by developing adaptive user interface components for a category of diverse users; the vision impaired. This paper presents a framework that allows run time adaptation of web components to suit vision impaired users by using a set of adaptive, reusable widgets. We developed a prototype using these adaptive components and evaluated its effectiveness through a case study and user study. Our results show that an such an adaptive user interface provides significant benefit in many key W3C accessibility areas, making the web more accessible for diverse end users.