Talk:Landolt C

Angle?
what is the angle ($$d\theta$$) of the openings in those c-shapes for a 6/6 viewer?

IOW; What is the angular resolution defining a 6/6 visual acuity?

Yuvalaviel 10:25, 20 December 2006 (UTC)
 * I assume one arc minute, same as for Snellen charts. --Random832 (contribs) 18:55, 27 May 2008 (UTC)

According to Russian textbooks on Ophthalmology, the gap can be seen at angle of one angular minute at the distance of seven meters. The "picture" of the gap on retina, created by lens, covering the area of one light receptor. —Preceding unsigned comment added by 93.116.210.25 (talk) 13:51, 18 January 2010 (UTC)

And what's wrong with that picture? I'm using Firefox 2.0.0.6 and no image appears... - Nmnogueira 15:37, 29 August 2007 (UTC)
 * Ditto, I'm using Safari 2.0.4 and no image. 66.84.234.61 09:54, 8 October 2007 (UTC)
 * Same problem... But if you save the SVG image to disk and then drag it to Firefox, it appears to display correctly. GregorB (talk) 00:51, 25 November 2007 (UTC)
 * Or if you go directly here. GregorB (talk) 12:14, 25 November 2007 (UTC)

Representation of Landolt C is inaccurate
Please note that the diagram https://en.wikipedia.org/wiki/File:Landolt_C.svg of the Landolt ring is rather inaccurate. As correctly stated in https://en.wikipedia.org/wiki/Landolt_C the width of the gap should be 1/5th of the diameter of the C reps. the stroke width of the C. In this diagram the gap clearly is too small.AlbertJanPool (talk) 08:45, 5 November 2013 (UTC)

I have updated the previous incorrect image with a correct one created in Illustrator with the 1:5 ratio. Borgendorf (talk) 05:13, 30 November 2021 (UTC)


 * But it is still incorrect now. The width of the gap is 1/6th of the diameter of the C reps. Programus (talk) 09:02, 14 April 2022 (UTC)
 * Is the result below with two charts correct? 2A00:1370:8184:2EA3:EDF2:3B82:5A6B:7F29 (talk) 14:17, 16 June 2022 (UTC)
 * as of today gap in C is still too narrow, viz. 8¼ background squares (not precise) out of 54 squares total
 * stroke of C correct, being approx. 11/54
 * see correct representation on wiki.de - https://de.wikipedia.org/wiki/Landoltring#/media/Datei:Landoltring_Abmessungen.jpg -
 * Sintermerte (talk) 16:12, 26 January 2023 (UTC)

Landlot c chart procedure uses
landlot c chart uses

49.15.93.235 (talk) 18:30, 21 January 2024 (UTC)