I have added a new test mode to FrACT₁₀. Its button is seen on the left, it denotes the new “line-by-line” mode. In contrast to the other test modes this one does not offer any automatic testing but rather displays a line of five optotypes, namely the Sloan letters (as also used in the ETDRS charts).
Initially the acuity grade is 0.3 LogMAR. Using the up/down cursor keys it can be changed in 0.1 LogMAR steps throughout the interesting range. The other cursor keys reshuffle the optotypes into a new random selection.
I added this mode on request. It allows to operate FrACT₁₀ like a chart; it’s even easier because only one line is presented at a time. Furthermore, this mode provides a useful target when optimising refraction.