Medicine:Jaeger chart

From HandWiki
Short description: Diagnostic tool

The Jaeger chart is an eye chart used in testing near vision 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.

References

  1. Blesi, Michelle; Wise, Barbara; Kelley-Arney, Cathy (2011). Medical Assisting Administrative and Clinical Competencies. Cengage Learning. pp. 888–890. ISBN 978-1133706960. https://books.google.com/books?id=7XMJAAAAQBAJ&pg=PA888. 
  2. G.K. & Pal; Pal; Pravati (1 February 2006). Textbook Of Practical Physiology (2nd ed.). Orient Blackswan. pp. 328–. ISBN 978-81-250-2904-5. https://books.google.com/books?id=XpUAihQ7Ib4C&pg=PA328. 
  3. Khurana (2008). Theory and Practice of Optics and Refraction. Elsevier India. p. 49. ISBN 9788131211328. https://books.google.com/books?id=qYeD3VHi8OsC&pg=PA49. 
  4. Colenbrander, August; Runge, Paul E. (May 2007). "Can Jaeger Numbers be Standardized? (Poster 3563)". Association for Research in Vision and Ophthalmology (ARVO) 2007 Annual Meeting, Fort Lauderdale. 48. 3563. http://iovs.arvojournals.org/article.aspx?articleid=2386268.