NCIt definition : A diagrammatic method to test visual acuity and contrast sensitivity, which utilizes
large letters (at a 20/60 acuity) that decrease in contrast from right to left and
top to bottom.;
Alternative definition : CDISC: A diagrammatic method to test visual acuity and contrast sensitivity, which
uses large letters (at a 20/60 acuity) that decrease in contrast from right to left
and top to bottom.;