FprEN ISO 9342-1
(Main)Optics and optical instruments - Test lenses for calibration of focimeters - Part 1: Reference lenses for focimeters used for measuring spectacle lenses (ISO/FDIS 9342-1:2023)
Optics and optical instruments - Test lenses for calibration of focimeters - Part 1: Reference lenses for focimeters used for measuring spectacle lenses (ISO/FDIS 9342-1:2023)
This document specifies requirements for reference lenses for the calibration and verification of focimeters that are used for the measurement of spectacle form lenses, e.g. those complying with ISO 8598-1. It also gives a method for the determination of the back vertex power of the reference lenses.
NOTE It is accepted that other reference lenses can also be used with powers within the given range, manufactured to the same standard of accuracy and form, but different back vertex powers. However, only lenses with integer nominal powers, as described in 4.1, can be used for the calibration of digitally-rounding focimeters.
Optik und optische Instrumente - Prüfgläser zur Kalibrierung von Scheitelbrechwert-Messgeräten - Teil 1: Referenzgläser für Scheitelbrechwert-Messgeräte für die Messung von Brillengläsern (ISO/FDIS 9342‑1:2023)
Dieses Dokument legt Anforderungen an Referenzgläser zur Kalibrierung und Überprüfung von Scheitelbrechwert-Messgeräten fest, die für die Messung von Brillengläsern verwendet werden, z. B. solche, die der ISO 8598 1 entsprechen. Es enthält auch ein Verfahren zur Bestimmung des bildseitigen Scheitelbrechwerts der Referenzgläser.
ANMERKUNG Die Verwendung anderer Referenzgläser, deren Brechwert im angegebenen Bereich liegt und die bezüglich Genauigkeit und Form gleichwertig gefertigt wurden, jedoch andere bildseitige Scheitelbrechwerte aufweisen, ist ebenfalls zulässig. Für die Kalibrierung von digital rundenden Scheitelbrechwert-Messgeräten können jedoch nur Gläser mit einem ganzzahligen Sollscheitelbrechwert, wie in 4.1 beschrieben, verwendet werden.
Optique et instruments d'optique - Verres étalons pour l'étalonnage des frontofocomètres - Partie 1: Verres de référence pour frontofocomètres pour le mesurage des verres de lunettes (ISO/FDIS 9342-1:2023)
Le présent document spécifie les exigences applicables aux verres de référence pour l'étalonnage et la vérification des frontofocomètres utilisés pour le mesurage des verres de lunettes, par exemple ceux qui sont conformes à l'ISO 8598-1. Il donne en outre une méthode qui permet de déterminer la puissance frontale arrière des verres de référence.
NOTE Il est admis que d'autres verres de référence ayant des puissances situées dans la plage donnée, fabriqués selon les mêmes normes d'exactitude et de courbure, mais ayant des puissances frontales arrière différentes, puissent être utilisés. Cependant, pour l'étalonnage des frontofocomètres à affichage numérique avec arrondi, on ne peut utiliser que des verres ayant des puissances nominales entières, comme décrit en 4.1.
Optika in optični instrumenti - Preskusne leče za umerjanje fokometrov – 1. del: Referenčne leče za fokometre, ki se uporabljajo za merjenje spektralnih leč (ISO/FDIS 9342-1:2023)
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Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN ISO 9342-1:2022
01-september-2022
Optika in optični instrumenti - Preskusne leče za umerjanje fokometrov – 1. del:
Referenčne leče za fokometre, ki se uporabljajo za merjenje spektralnih leč
(ISO/DIS 9342-1:2022)
Optics and optical instruments - Test lenses for calibration of focimeters - Part 1:
Reference lenses for focimeters used for measuring spectacle lenses (ISO/DIS 9342-
1:2022)Optik und optische Instrumente - Prüfgläser zur Kalibrierung von Scheitelbrechwert-
Messgeräten - Teil 1: Referenzgläser für Scheitelbrechwert-Messgeräte für die Messung
von Brillengläsern (ISO/DIS 9342‑1:2022)Optique et instruments d'optique - Verres étalons pour l'étalonnage des frontofocomètres
- Partie 1: Verres de référence pour frontofocomètres pour le mesurage des verres de
lunettes (ISO/DIS 9342-1:2022)Ta slovenski standard je istoveten z: prEN ISO 9342-1
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
oSIST prEN ISO 9342-1:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 9342-1:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 9342-1
ISO/TC 172/SC 7 Secretariat: DIN
Voting begins on: Voting terminates on:
2022-06-10 2022-09-02
Optics and optical instruments — Test lenses for
calibration of focimeters —
Part 1:
Reference lenses for focimeters used for measuring
spectacle lenses
Optique et instruments d'optique — Verres étalons pour l'étalonnage des frontofocomètres —
Partie 1: Verres étalons pour frontofocomètres pour le mesurage des verres de lunettes
ICS: 11.040.70This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 9342-1:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
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oSIST prEN ISO 9342-1:2022
ISO/DIS 9342-1:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
© ISO 2022 – All rights reserved
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oSIST prEN ISO 9342-1:2022
ISO/DIS 9342-1:2022(E)
Contents Page
Foreword ........................................................................................................................................................................................................................................iv
1 Scope ................................................................................................................................................................................................................................. 1
2 Normative references ..................................................................................................................................................................................... 1
3 Terms and definitions .................................................................................................................................................................................... 1
4 Design requirements and recommendations for reference lenses ...............................................................3
4.1 General ........................................................................................................................................................................................................... 3
4.2 Spherical reference lenses ............................................................................................................................................................ 3
4.2.1 Standard reference lenses .......................................................................................................................................... 3
4.2.2 Low power reference lenses (optional) .......................................................................................................... 4
4.3 Prismatic reference lenses ........................................................................................................................................................... 4
4.4 Cylindrical reference lenses........................................................................................................................................................ 5
4.5 Spherocylindrical-power reference lenses .................................................................................................................... 5
4.6 Reference filter ....................................................................................................................................................................................... 6
4.7 Darker reference filters (optional) ....................................................................................................................................... 6
5 Uncertainties and Tolerances ................................................................................................................................................................ 7
5.1 Uncertainties for spherical reference lenses ............................................................................................................... 7
5.2 Uncertainties for prismatic reference lenses .............................................................................................................. 8
5.3 Tolerance for the axis of the cylindrical reference lens ..................................................................................... 8
Annex A (informative) Design of spherical reference lenses .................................................................................................... 9
Annex B (informative) Design and/or validation of prismatic reference lenses ...............................................13
Annex C (informative) Verification of the cylindrical reference lens ...........................................................................16
iii© ISO 2022 – All rights reserved
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oSIST prEN ISO 9342-1:2022
ISO/DIS 9342-1:2022(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.The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www.iso.org/iso/foreword.html.This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee
SC 7, Ophthalmic optics and instruments.This second edition cancels and replaces the first edition (ISO 9342-1:2005), which has been technically
revised.A list of all parts in the ISO 9342 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.© ISO 2022 – All rights reserved
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oSIST prEN ISO 9342-1:2022
DRAFT INTERNATIONAL STANDARD ISO/DIS 9342-1:2022(E)
Optics and optical instruments — Test lenses for
calibration of focimeters —
Part 1:
Reference lenses for focimeters used for measuring
spectacle lenses
1 Scope
This part of ISO 9342 specifies requirements for reference lenses for the calibration and verification of
focimeters that are used for the measurement of spectacle form lenses. It also gives a method for the
determination of the back vertex power of the reference lenses.NOTE It is accepted that other reference lenses can also be used with powers within the given range,
manufactured to the same standard of accuracy and form, but different back vertex powers. However, only lenses
with integer nominal powers, as described in paragraph 4.1, can be used for the calibration of digitally-rounding
focimeters.2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 7944, Optics and optical instruments — Reference wavelengthsISO 8598-1, Optics and optical instruments — Focimeters — Part 1: General purpose instruments
ISO 13666, Ophthalmic optics — Spectacle lenses — Vocabulary3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13666 as well as the following
apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp— IEC Electropedia: available at https:// www .electropedia .org/
3.1
back vertex power
reciprocal of the paraxial value of the back vertex focal length
Note 1 to entry: According to ophthalmic convention, the “power” of a lens is specified as the back vertex power.
Note 2 to entry: The unit for expressing focal length is the metre and for vertex power is the reciprocal metre (m ).
The name for this unit is “dioptre”, and the symbol is “D”.[SOURCE: ISO 13666:2019, 3.10.8, modified by adding note 2 to entry.]
© ISO 2022 – All rights reserved
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oSIST prEN ISO 9342-1:2022
ISO/DIS 9342-1:2022(E)
3.2
reference lens
lens complying with this document used for the calibration and verification of focimeters
3.3spherical reference lens
lens with spherical front and back surfaces used for the calibration and verification of dioptric power
measurements by focimetersNote 1 to entry: A surface of plano power is a special case of a spherical surface having an infinite radius of
curvature.3.4
prismatic reference lens
prismatic lens constructed with two plane surfaces used for the calibration and verification of prismatic
power measurements by focimetersNote 1 to entry: The unit for expressing prismatic power is centimetres deviation per metre distance (cm/m).
The name for this unit is “prism dioptre” and the symbol is “Δ”.Note 2 to entry: The prism shall be constructed to give the correct deviation with light incident perpendicular to
one surface.3.5
cylindrical reference lens
lens with one plane surface and one cylindrical surface used to calibrate and verify the axis indicator
and axis marker with reference to the orientation of the adjusting rail3.6
spherocylindrical-power reference lens
lens with one spherical surface and one toroidal surface that are used to check the non-symmetric
cylinder power and cylinder axis error given by an automated focimeter after calibration
3.7reference filter
neutral density filter of plano power that is used to check the capability of an automated focimeter to
measure tinted lenses3.8
surface power
capacity of an optical surface to change the curvature of incident wavefronts by refraction
Note 1 to entry: Back surface power is given by the formula:F = (1 – n)/r
BS 2
where
F is the back surface power in D;
n is the refractive index of the material of the lens, and
r is the radius of curvature of the back surface in metres, regarded as being positive if the centre of
curvature is behind the surface according to the direction of travel of light through the surface.
[SOURCE: ISO 13666:2019, 3.2.10, modified by the deletion of 'of a lens' and 'or deviation' and the
addition of Note 1 to entry.]© ISO 2022 – All rights reserved
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oSIST prEN ISO 9342-1:2022
ISO/DIS 9342-1:2022(E)
3.9
verified power
power derived from measurements of the parameters of the reference lens
Note 1 to entry: Each verified power comes with an uncertainty. This uncertainty is derived from the
uncertainties of the individual measurements used to establish the verified power and must be within the values
specified in this document.Note 2 to entry: An example for the set of parameters to be measured for a spherical reference lens, are the
refractive index, radii of curvature of the two surfaces and thickness (see Annex A). For a prismatic reference
lens, an example for a set of parameters to be measured are the refractive index and its apical angle (i.e. the angle
between its two surfaces). (See Annex B).Note 3 to entry: These parameters are measured using procedures and/or equipment traceable to certificates
issued by an appropriate metrology laboratory4 Design requirements and recommendations for reference lenses
4.1 General
All reference lenses shall be made of homogeneous white crown glass selected to be free of bubbles and
striae in an area of 4 mm radius surrounding the centre of the aperture.Other materials may also be used provided their use results in lenses with a durability and optical
reproducibility within the given tolerance over time and that can be manufactured to the same standard
of uncertainty and form as the glass lenses specified above.The reference wavelength for the reference lenses used to calibrate and calculate the conventional
power value of the back vertex power shall be stated. The reference wavelengths shall be either the
green mercury e line (λe = 546,07 nm) or the yellow helium d-line (λd = 587,56 nm).
The conventional power value of a reference lens is defined as a calculated value, which is based on
actual measurements of the individual design parameters of the reference lens, such as refractive
index, radius of curvature of lens surface, etc. These are measured using procedures and/or equipment
traceable to certificates issued by an appropriate metrology laboratory. An appropriate metrology
laboratory may be one accredited to ISO 17025 for these measurements or one specified in national or
regional regulations.NOTE The reference lenses should have protective mounts, which are designed so that, when a lens is
correctly placed on the lens support, the focimeter is not obstructed. It is recommended that the verified power
value of the power of the lens and the reference wavelength be marked on the mount.
4.2 Spherical reference lenses4.2.1 Standard reference lenses
For a complete set of spherical reference lenses, the following set of nominal back vertex powers is
recommended:−25 D, −20 D, −15 D, −10 D, −5 D, +5 D, +10 D, +15 D, +20 D, +25 D
The spherical reference lenses should have an aperture of at least 15 mm.
In order to minimize the influence of spherical aberration, the curvature of the back surface and the
centre thickness shall approximately correspond to those of normal spectacle lenses. Table 1 gives
nominal back surface powers and ranges for centre thickness, which will ensure that the reference
lenses are of this form.© ISO 2022 – All rights reserved
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oSIST prEN ISO 9342-1:2022
ISO/DIS 9342-1:2022(E)
Table 1 — Design range for the standard spherical reference lenses
Range for back surface
Nominal back vertex power Range for centre thickness
power
D D mm
−25 -26 to -24 2 to 6
−20 -21 to -19 2 to 6
−15 -16 to -14 2 to 6
−10 -13 to -11 2 to 8
−5 -10 to -8 2 to 8
+5 -6 to -4 3 to 7
+10 -4 to -2 3 to 7
+15 -2 to 0 5 to 7
+20 -1 to 0 7 to 9
+25 -1 to 0 9 to 11
The centre thicknesses are required to guarantee stability in the negative power range.
The back surface shall not be convex4.2.2 Low power reference lenses (optional)
When validating automated instruments, it is recommended to add extra, low, powers into the range.
Suggested values can be found in Table 2.Table 2 — Design range for the low power spherical reference lenses
Nominal back vertex Nominal back surface Power range for back Range for centre thick-
power power surface power nessD D D mm
–2,5
–0,25
–0,12
–6 ± 1 2 to 8
+0,12
+0,25
+2,5
The centre thicknesses are required to guarantee stability in the negative power range.
Choose either +0,25 and-0,25 or +0,12 and -0,12.4.3 Prismatic reference lenses
The optical surfaces of prismatic reference lenses shall be plane and their aperture shall be at least
15 mm.The number of prismatic reference lenses that should be used to adjust or to check a focimeter depends
on the measuring range of the instrument. The prismatic power marked on the mount shall be the
power for light incident normal to the surface resting on the lens support.For a complete set, the following set of prismatic powers is recommended:
2 Δ 5 Δ 10 Δ 15 Δ 20 Δ
NOTE The prismatic value may depend on the design of the focimeter (IOA or FOA – see ISO 13666) due to
the implications of incident angle. This is explained in ISO/TR 29890.© ISO 2022 – All rights reserved
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oSIST prEN ISO 9342-1:2022
ISO/DIS 9342-1:2022(E)
4.4 Cylindrical reference lenses
This reference lens shall be a positive plano-cylindrical lens of at least 5 D edged to a rectangular shape
and shall have the dimensions, nominal unless otherwise stated, shown in Figure 1. The cylinder axis
shall be parallel to the longer, reference, side of the rectangle and shall be marked by a centre line. The
reference side shall also be marked.Dimensions in millimetres
Key
1 Centre line
2 Reference side/edge
Figure 1 — Cylindrical reference lens
4.5 Spherocylindrical-power reference lenses
Spherocylindrical-power reference lenses are used to test automated focimeters that measure sphere
power, cylinder power, and cylinder axis simultaneously for non-symmetric cylinder power and cylinder
axis errors. They are specially mounted spherocylindrical-power lenses with a power of –2,00 D sph/–
1,50 D cyl, of spectacle form and quality conforming to ISO 8980-1, and shall have a diameter of not less
than 25 mm.The spherocylindrical-power reference lens is centred and firmly affixed on to an octagonal disk so
that the optical centre of the lens is coincident with the geometrical centre of the disk. The length of
the sides of the disk shall be between 25 mm and 30 mm. The axis of the cylinder should be aligned
as close as practicable to one of the faces of the disk. The disk shall have a clear central aperture of at
least 10 mm diameter centred on the geometrical centre of the disk. The disk is constructed of metal or
rigid plastic at least 3 mm in thickness.An illustration of the specially mounted spherocylindrical-power reference lens with the disk is shown
in Figure 2.As an alternative to using a lens mounted on an octagonal disc, a lens may be edged to the same
octago...
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