Diagnostic tool
The Jaeger chart is an eye chart used in testing near visual acuity. It is a card on which paragraphs of text are printed, with the text sizes increasing from 0.37 mm to 2.5 mm.[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.[3]
Jaeger cards are not standardized, and the variability of the actual size of test letters on different Jaeger cards currently in use is very high.[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.
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