[1] This card is to be held by a patient at a fixed distance from the eye dependent on the J size being read.
The smallest print that the patient can read determines their visual acuity.
[2] The original 1867 chart had a text containing seven paragraphs and a corresponding seven-point scale.
[4] Therefore, test results with different Jaeger cards are not comparable.
More commonly, distance vision acuity is tested using the Snellen chart, familiarly seen wall mounted with a large letter at the top.