—The graphic three-step test is a simple method for accurately analyzing cyclovertical muscle palsies. It should not be considered a gimmick just because it does not stress the anatomy or physiology of the extraocular muscles to the same extent that other methods do.An even more powerful technique exists for analyzing cyclovertical muscle palsies and I refer Dr Ruttum to this article.1 In this article I show that the usual anatomic reasoning used to analyze cyclovertical muscle palsies may be entirely replaced by the mathematical operation of obtaining the decimal equivalent of a binary number. Using this result and a BCD (binary-coded decimal) integrated circuit chip, an ophthalmologist may analyze cyclovertical muscle palsies by setting the position of three switches and noting which LED (light-emitting diode) lights up.
Vazquez RL. Graphic Three-Step Test-Reply. Arch Ophthalmol. 1984;102(6):824. doi:10.1001/archopht.1984.01040030650006