Visual Aids For Eye Testing (USA)
This is a Visual aids for eye testing.
This booklet of simple eye tests from the 1930s captures a host of assumptions about people and their cultural competencies, from card playing and singing to understanding train schedules and shorthand. The first standardized eye chart is believed to have been developed by Dutch ophthalmologist Herman Snellen in 1862. Snellen’s test of visual acuity set a standardized distance from patient to chart of 20 feet in the United States and 6 meters in Europe. This inexpensive and portable chart has eleven lines of symbols, called optotypes, from a single large letter at the top to the smallest letters at the bottom. The letters are carefully shaped so as to balance the amount of white to black space. Similar charts followed, such as the Lea chart designed in Finland in 1976 that uses objects, like a house or a ring, to cater to children and others who are preliterate.
It is credited
Smithsonian Institution, National Museum of American History, 1986.0705.03.
Our curators have highlighted 8 objects that are related to this one. Here are three of them, selected at random:
Its dimensions are
H x W x D (closed): 20.5 x 12 x 1.5 cm (8 1/16 x 4 3/4 x 9/16 in.) H x W x D (open): 20.5 x 24 x 1.5 cm (8 1/16 x 9 7/16 x 9/16 in.)
This object was previously on display as a part of the exhibition Tools: Extending Our Reach.