Abstract:Reading acuity testing is widely implemented in ophthalmology field such as visual function inspection and low vision rehabilitation. However, when using the printed version of reading acuity chart in clinics, it’s unable to quantify the illuminance, display the sentences line by line or automatically collect and analyze testing data. Meanwhile due to the difficulty of displaying the minimum target in display with extremely high pixel density, there is no such an automatic instrument at home and abroad. Given all that problems, a reading acuity test instrument was designed with customized LCD module, Bluetooth 4.2 module, STM8105 as the main processor. This App controlled device has the capabilities to perform reading acuity test through Bluetooth communication and automatic speech recognition. And has the advantage of high inspection accuracy, automatic analysis of testing results, and strong applicability. The experimental tests show that this design meets the standard accuracy demands. And there is a well applied prospect in the ophthalmology field in both examination and rehabilitation.