EN ISO 12865:1998
(Main)Ophthalmic instruments - Retinoscopes (ISO 12865:1998)
Ophthalmic instruments - Retinoscopes (ISO 12865:1998)
Specification of minimum requirements in order to guarantee a sufficient quality of use.
Ophtalmische Instrumente - Skiaskope (ISO 12865:1998)
Diese Internationale Norm legt zusammen mit ISO 15004 Mindestanforderungen und Prüfverfahren für handgehaltene Strich- und Fleckskiaskope fest, die zur objektiven Ermittlung von Refraktionsfehlern des Auges benutzt werden. Wenn Unterschiede vorliegen, hat diese Internationale Norm Vorrang vor ISO 15004.
Instruments ophtalmiques - Rétinoscopes (ISO 12865:1998)
Oftalmični instrumenti - Retinoskopi (ISO 12865:1998)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 12865:2000
01-januar-2000
2IWDOPLþQLLQVWUXPHQWL5HWLQRVNRSL ,62
Ophthalmic instruments - Retinoscopes (ISO 12865:1998)
Ophtalmische Instrumente - Skiaskope (ISO 12865:1998)
Instruments ophtalmiques - Rétinoscopes (ISO 12865:1998)
Ta slovenski standard je istoveten z: EN ISO 12865:1998
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
SIST EN ISO 12865:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 12865:2000
INTERNATIONAL ISO
STANDARD 12865
First edition
1998-06-15
Ophthalmic instruments — Retinoscopes
Instruments ophtalmiques — Rétinoscopes
A
Reference number
ISO 12865:1998(E)
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ISO 12865:1998(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. Each 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 12865 was prepared by Technical Committee
ISO/TC 172, Optics and optical instruments, Subcommittee SC 7,
Ophthalmic optics and instruments.
Annex A forms an integral part of this International Standard. Annexes B and
C are for information only.
© ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
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INTERNATIONAL STANDARD ISO ISO 12865:1998(E)
Ophthalmic instruments — Retinoscopes
1 Scope
This International Standard, together with ISO 15004, specifies minimum requirements and test methods for hand-held
streak and spot retinoscopes for use in objective determination of the refractive errors of the eye.
This International Standard takes precedence over ISO 15004, if differences exist.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility
of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of
currently valid International Standards.
ISO 15004:1997, Ophthalmic instruments — Fundamental requirements and test methods
IEC 60601-1:1988, Medical electrical equipment — Part 1 : General requirements for safety
3 Definitions
For the purposes of this International Standard, the following definitions apply.
3.1
retinoscope
ophthalmic instrument designed to assess objectively refractive errors of the eye by reflecting a beam of light into it
from a mirror and observing the movement of the retinal reflex across the pupil
NOTE - A retinoscope usually consists of an illuminating system that produces a beam of light including a mirror with
either a semireflective or a perforated highly reflective coating, a viewing system and a power supply for the light source.
3.2
streak retinoscope
retinoscope capable of producing a beam of light of rectangular cross-section with adjustable focusing
3.3
spot retinoscope
retinoscope capable of producing a beam of light of approximately circular cross-section
NOTE - The spot image focus may be adjustable.
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4 Requirements
4.1 General
The retinoscope shall conform to the requirements specified in ISO15004.
The retinoscope shall conform to the specific requirements specified in 4.2 to 4.4.
These requirements are verified as specified in clause 5.
4.2 Optical and mechanical requirements
The requirements specified in table 1 shall apply.
Table 1 -— Requirements for optical and mechanical specifications
Retinoscope Criterion Requirement
o
Rotation > 190
1)
Distance of real image of lamp filament adjustable to < 450 mm
1)
Streak Distance of virtual image of lamp filament adjustable to < 450 mm
2)
retinoscope Length of streak image > 30 mm
2)
Thickness of streak image < 1,5 mm
2)
Deviation from linearity of the streak image at the focus < 2 mm
2)
Rotational decentring of centre of streak image < 10 mm
1)
Spot Distance of virtual image of lamp filament < 1000 mm
1)
retinoscope Spot diameter at 500 mm distance < 25 mm
1) All distances are measured from the light exit of the instrument.
2) When focused at 500 mm.
4.3 Construction and function
4.3.1 General
a) When projecting the light beam onto a white surface and looking through the instrument, no internal reflection or
scattered light shall be visible.
b) The light output shall be adjustable, continuously or in steps, from zero to its maximum.
4.3.2 Streak retinoscopes
a) The streak image shall be continuously rotatable within the limits specified in table 1.
b) The streak imaging bundle of light shall be continuously adjustable from convergent to divergent within the image
distances specified in table 1.
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c) The streak image shall be evenly illuminated and free from discoloration and distortion.
NOTE - An index stop at the infinite focus is optional.
4.4 Optical radiation hazard with retinoscopes
4.4.1 General
This clause replaces clauses 32, 33 and 34 of IEC 60601-1:1988.
4.4.2 Limit values
The limit values given in items a) and b) shall apply to the radiation emerging from the retinoscope used to illuminate
and view the human eye with light from 380 nm to 700 nm and in which the full beam homogeneously illuminates a
circular pupil of 8 mm diameter (see notes 2 and 4).
a) Short wavelength limit:
The radiance of the light source in the portion of the spectrum from 305 nm to 400 nm shall be no greater than
2
1,6 mW/(cm · sr) as measured in the beam exiting the retinoscope with the instrument operating at maximum
1)
intensity .
NOTE 1 For retinoscopes with a small illuminating solid angle, i.e. Ω << 0,031 sr, the limit value of illumination is
given by the radiance of the light source instead of an irradiance value in the corneal plane.
b) Long wavelength limit:
The amount of energy exiting the retinoscope in the wavelength range 700 nm to 1100 nm shall not exceed
2
100 mW/cm , nor shall it exceed the amount of energy exiting the retinoscope in the range between 380 nm and
700 nm. The energy shall be measured in the corneal plane when the instrument is operating at maximum
1)
intensity .
NOTE 2 If, due to stops or other obstructions of the beam, a circular pupil of diameter less than 8 mm is illuminated,
the limit values may be increased by the ratio of the area of an 8 mm diameter pupil divided by the true area
illuminated.
NOTE 3 It is recommended that the energy in the range of the spectrum below 420 nm be attenuated as much as
possible.
NOTE 4 For retinoscopes, the assumptions used to set the limit value for radiation of wavelength shorter than
400 nm are based on considerations of the typical spectral distribution of a 3000 K standard black-body source, a
maximum exposure time of 5 min and the weighting factors for L (see Annex A). The limit is set to ensure that the
A
fraction of the photochemical hazard dose due to radiation of wavelength shorter than 400 nm is no greater than 1/8 of
the total photochemical hazard dose over all wavelengths when that total dose is at the threshold limit for an 8 mm
diameter pupil.
Using the American Conference of Governmental Industrial Hygienists (ACGIH) guidelines, that threshold limit is
14 J/(cm² · sr). To convert from photochemical hazard weighted radiance to radiance over the designated spectral
range (305 nm to 400 nm), the conversion factor 0,276 is used. Thus the limit is then found by the formula
[14 J/(cm² · sr)] · [0,276/(300 s 3 8)] = 1,6 mW/(cm² · sr)
1) Maximum intensity is the highest brightness the retinoscope is capable of delivering, including the highest brightness
achievable if overvoltage is provided.
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4.4.3 Variable brightness
For retinoscopes where provision is made to vary the brightness, the manufacturer shall provide indications of the
proportions of the maximum intensity.
4.4.4 Particular information
The manufacturer shall provide the user with a graph showing the relative spectral output of the retinoscope
between 305 nm and 1100 nm when the instrument is operating at maximum light intensity. The spectral output
shall be shown for the beam after it exits the instrument.
The manufacturer shall provide the user with the values for the spectrally weighted photochemical source radiance,
both phakic L and aphakic L , measured in the beam exiting from the instrument when operating at maximum
B A
intensity and determined by using the spectral weighting values given in Annex A.
The manufacturer shall provide information on the meaning of L and L to the user.
B A
NOTE - An example of such information is given in Annex C.
5 Test methods
All tests described in this International Standard are type tests.
5.1 Checking the optical, mechanical and functional requirements
5.1.1 The requirements specified
...
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