Stilling Test

The original pseudoisochromatic plate test for color vision, released in 1876. At the time, it was a massive improvement to the most common color vision test at the time: Holmgren’s Wool. Foremost, it was based on the burgeoning Opponent Process Theory (Tetrachromatic Color Theory) instead of Holmgren’s misunderstandings of the Young-Helmholtz Theory (Trichromatic Color Theory). Stilling also chose the colors of confusion based on the perception two assistants: a red-green colorblind painter and a blue-yellow colorblind teacher.

Although the Stilling Test was published 40 years before the now ubiquitous Ishihara Test, by the 1950s, the Stilling Test had been largely supplanted by the Ishihara Plates and later the more modern HRR Plates. The decline is attributed to mismanagement by Stilling’s successor (Hertel) in later editions, not necessarily because the Ishihara offered improvements (Murray 1943).

Unlike the Ishihara, the Stilling Test includes plates for blue-yellow CVD.