The<unk>  was created by Ferdinand<unk>  and is used to test visual acuity. He inserted his name in the<unk> ; reading upwards on both ends, but ignoring the first line, the name "Ferdinand<unk> " can be seen.
Monoyer chart
Jaeger chart
Lund and Browder chart
Ogden tables
Darrow Yannet diagram
Haller index
Barber–Johnson diagram
Mentzer index