Holmgren yarn test

noun
Holm·​gren yarn test | \ ˈhōm-grən-ˈyärn-, ˈhōlm- How to pronounce Holmgren yarn test (audio) \

Medical Definition of Holmgren yarn test

: a method of testing color vision by the use of colored wool yarns

called also Holmgren test, Holmgren wool test