EN ISO 8597:1996

SLOVENSKI STANDARD
01-januar-2000
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Optics and optical instruments - Visual acuity testing - Method of correlating optotypes
(ISO 8597:1994, including Technical Corrigendum 1:1995)
Optik und optische Instrumente - Sehschärfeprüfung - Verfahren zum Anschluß von
Sehzeichen (ISO 8597:1994, einschließlich Technische Korrektur 1:1995)
Optique et instruments d'optique - Méthode d'essai de l'acuité visuelle - Méthode de
corrélation entre les optotypes (ISO 8597:1994, Rectificatif Technique 1:1995 inclus)
Ta slovenski standard je istoveten z: EN ISO 8597:1996
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 8597
First edition
1994-09-15
.Optics and Optical instruments - Visual
- Method of correlating
acuity testing
optotypes
Op tique et instruments d ’optique - Methode d ’essai de I ’acuit6
visuelle - Methode de corrbla tion en tre les optotypes
Reference number
ISO 8597: 1994(E)
ISO 8597:1994(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national Standards bodies (ISO member bodies). The work
of preparing International Standards is normally carried out through ISO
technical committees. Esch member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 8597 was prepared by Technical Committee
ISO/TC 172, Optics and optica/ instruments, Subcommittee SC 7,
Ophthalmic, endoscopic, metrological instruments and test methods.
0 ISO 1994
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-l 211 Geneve 20 l Switzerland
Printed in Switzerland
ii
INTERNATIONAL STANDARD 0 ISO ISO 8597:1994(E)
Optics and Optical instruments - Visual acuity
testing - Method of correlating optotypes
NOTE 1 If letters or figures are used for visual acuity
1 Scope
measurement, then it should be acknowledged that these
normally show large differentes in respect of
This International Standard specifies a method of cor-
recognizability, even if their size and thickness of stroke are
relation between a given set of optotypes and the
identical. The disadvantages of their use tan be reduced by
Standard optotype (Landolt ring) specified by
choosing letters or figures which are comparable with each
ISO 8596.
other.
4 Correlation of optotypes
2 Normative reference
The following Standard contains provisions which,
4.1 Standard optotypes
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
The optotype sizes (grades) specified in ISO 8596
cation, the edition indicated was valid. All Standards
shall be used. Sufficient grades or Steps shall be used
are subject to revision, and Parties to agreements
to establish a frequency of seeing curve for the stan-
based on this International Standard are encouraged
dard optotype and the optotype being investigated.
to investigate the possibility of applying the most re-
cent edition of the Standard indicated below. Mem-
4.2 Test area
bers of IEC and ISO maintain registers of currently
valid International Standards.
The test area shall be circular with a diameter of
4” + 0,4 ”.
-
ISO 8596:1994, Ophthalmic optics - Visual acuity
testing - Standard optotype and its presentation.
The surrounding field shall have a diameter of
15” + 1,5 % and shall be illuminated homogeneously
so that it does not influence the measurement.
3 General requirements for optotypes
The luminance of the surrounding field shall not be
For all optotypes, the requirements and method of
greater than that of the test area.
use given in ISO 8596 shall appply, .unless otherwise
specified in this International Standard.
4.3 Presentation of the optotypes
Esch size of a set of optotypes shall be specified in
In m
...