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Hermann, Dutch ophthalmologist, 1834-1908. See: Snellen sign, Snellen test types.
Farlex Partner Medical Dictionary © Farlex 2012
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Subsequently, data for patients with an initial Snellen fraction of 20/20 or better were deleted, and the remaining pooled data for the two eyes were compared, pre- and post-treatment, with the Wilcoxon signed rank test.
During this time 26.2% of eyes experienced a worsening of visual acuity, dropping from a mean of LogMAR 0.84 to LogMAR 1.84 (Snellen 6/40 to <1/60; p<0.0001).
Participants' ages ranged from 54 to 87 years (mean [+ or -] standard deviation [SD]: 75.10 [+ or -] 8.92 years), with a mean visual acuity (measured by Lighthouse Visual Acuity charts) in their better eye of 0.82 logMAR or 20/126 Snellen equivalent (SD = 0.31) and mean Pelli-Robson contrast sensitivity of 0.99 [+ or -] 0.42.
The more it tells you, the less you know.' This quotation by Diane Arbus, with which Corbey opens his book, captures the ambivalence and ambiguity inherent in the pictures displayed in Snellen om namen; De Marind-Anim van Nieuw-Guinea door de ogen van de Missionarissen van het Heilig Hart, 1905-1925 (Killing for names; The Marind Anim of New Guinea through the eyes of missionaries of the Sacred Hart, 19051925).
Final visual outcome was defined as Snellen's or LogMar best corrected visual acuity at final follow up of 120 days after the onset of central retinal vein occlusion and compared with the presenting visual acuity.
Snellen's team observed Osiris for five hours last August, using the European Southern Observatory's Very Large Telescope (VLT) in the desert of Chile.
While the CD and appendix are handy, these features and assistance with converting Snellen acuity to LogMAR acuity are just an added bonus.
Going far beyond the quality of vision indicated by Snellen testing, Holladay (ophthalmology, Baylor College of Medicine) helps surgeons better understand the machinery, instruments, technology and procedures commonly used to assess vision before and after cataract and refractive surgery, and designs this to be a daily handbook as well as a desk reference.
"It's very difficult to get work shown if it has a gay content to it, especially figurative work," says Wayne Snellen, Leslie/Lohman director.
Screening procedures, location of screening, lighting, and distance from the Snellen chart vary from school to school, and most schools do not comply with the standard.
It refers to central visual acuity of 20/200 or less in the better eye with the best possible correction, as measured on a Snellen vision chart, or a visual field of 20 degrees or less.