[2] Holmgren's test quickly established itself as a systematic and reliable method of detecting color blindness in railway and shipping workers.

[1][3] The original Holmgren test was the first successful attempt to standardize the detection of color blindness.

In 1879, the American government commissioned Thomson to conduct a color-blind inspection for railroads and shipping.

Thompson worked to simplify Holmgren's method so that a "non-professional" test could be performed and the results can be forwarded to an expert for interpretation.

[5] In Holmgren's wool test, the patient is asked to match coloured skeins of yarn to the samples in the box.