Visibility Vol 7 Issue 4, 2013

The MNREAD ACUITY CHARTS are continuous-text reading-acuity charts suitable for measuring the reading performance of normal and low-vision subjects. This test can be used in both clinical and research domains to measure three aspects of reading: 1) READING ACUITY (the smallest print that the subject can read); 2) CRITICAL PRINT SIZE (the smallest print that the subject can read with maximum speed); and 3) MAXIMUM READING SPEED (the subject’s reading speed when reading is not limited by print size). Here, we describe our first steps in designing and testing a digital version of the English MNREAD acuity charts, implemented on an iPad 3 with Retina display. In order to assess the equivalence between the hard-copy chart and the iPad 3 versions, we focused on two main questions: 1) Do the chart and iPad versions of the MNREAD test yield similar estimates for the three aspects of reading listed above? 2) What range of print sizes can be accommodated on the iPad 3, given the limitations due to screen size for large print and pixel resolution for small print.