Lea test

Dr. Hyvärinen completed her thesis on fluorescein angiography and helped start the first clinical laboratory in that area while serving as a fellow at the Wilmer Eye Institute of Johns Hopkins Hospital in 1967.

[citation needed] In addition to this, the LEA symbols test has been experimentally verified to be both a valid and reliable measure of visual acuity.

[3] A study published in Acta Ophthalmologica Scandinavica in 2006[4] showed that the Lea Symbols 15-line folding distance chart is clinically useful in detecting deficiencies in visual acuity in preschool children.

Most of the LEA tests can also be used on children with significant brain damage and serve as one of the few methods that can accurately assess visual acuity in these situations.

Because these four symbols can be named and easily identified as everyday, concrete objects ("apple", "house", "window", and "ring"), they can be recognized at an earlier age than abstract letters or numbers can be.

This enables preschool children to be tested for visual acuity long before they become familiar with the letter and numbers used in other standard vision charts.

This puzzle incorporates color along with the four standard optotypes to allow for measurement of visual acuity in children as young as fourteen months of age.