Now a days touch screen mobiles are becoming more popular amongst sighted as well visually impaired people due to its simple interface and efficient interaction techniques. Most of the touch screen devices designed for visually impaired users based on screen readers, haptic and different user interface (UI).In this paper we present a critical review of different keypad layouts designed for visually impaired users and their effect on text entry speed. And try to list out key issues to extend accessibility and text entry rate of touch screen devices.Keywords: Text entry rate, touch screen mobile devices, visually impaired users