Kids ASK! about Health & Fitness
When I was a kid, I used to wonder what 6/6 stands for (but I did not have a librarian to ask and no one told me the answer). I would spend time staring at the health cards when the nurses came around to do the yearly checkups and wondering if my eye-sight has deteriorated when I saw something that is not 6/6—I had perfect eyesight until I was 18 years old and considering that I used to read in bed, that was quite an achievement (kids… DO NOT follow my example. DO NOT read in bed lying down).
The accuracy of vision is usually referred to as “Snellen” acuity, after Dutch ophthalmologist, Hermann Snellen (1834-1908). That is the guy who created the chart and letters we now commonly use. The accuracy of vision/visual acuity refers to how clear one’s vision is.
6/6 is actually the distance from the patient in the eye exam room to the eye chart, 6 being 6 meters. Sometimes “20” is used because in the United States, 6 meters would be about 20 feet. If you were in the States and you had normal vision, you would get 20/20, which is the same as having 6/6.
There is actually additional information regarding what 6/6 means exactly. The distance of 6 meters actually corresponds to the visual angle of your eye. However, it is difficult to explain it without diagrams so I shall not reinvent the wheel but rather, direct you to the source of this information, which explains the whole concept of 6/6 quite extensively.
Anatomy, Physiology & Pathology of the Human Eye: Visual Acuity by Ted Montgomery
Montgomery, T. Visual Acuity. Retrieved January 9, 2008, from Anatomy, Physiology & Pathology of the Human Eye Web site: http://www.tedmontgomery.com/the_eye/index.html
If you want to find out more information on the eye
Eyes and ears by Simon, Seymour
Publisher : New York : HarperCollins Publishers, c2003
Call No. : J 612.8 SIM
Sight by Pringle, Laurence P
Publisher : New York : Benchmark Books, 2000
Call No. : J 597.3 PAR
Human Body by Bingham, Caroline
Publisher : London : Dorling Kindersley, 2003
Call No. : J 612 BIN
All websites are last accessed on 9 January 2008. Please refer to the terms and conditions on the homepages for use.
All images used are extracted from http://www.amazon.com and http://www.bn.com.
For the availability of the above book titles, please check the library catalogue.
Originally answered by Koh Chee Boon, Librarian, Children’s Services
Contributed by Felicia Chan, Librarian, Children’s Services
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