The Acuity App allows you to precisely measure your own visual acuity using an eye chart. To use this app, you will need 20 feet or 6 meters of room from your monitor. First, calibrate the app by entering the height of the letter E in the Calibration tab. Next, adjust the chart settings so that some lines are easy and some are difficult to read from a distance. Then click the Randomize button, stand 20 feet back, and record your best guess for each letter. Once you are done, enter the number of correct letters in the scoring tab. It will calculate your LogMAR score and its Snellen equivalent.