ISO/FDIS 9680

Formatted: French (Switzerland)
ISO/DISFDIS 9680
Formatted: French (Switzerland)
ISO/TC 106/SC 6
Secretariat: DIN
Date: 2025-10-152026-01-23
Dentistry — Operating lights
Médecine bucco-dentaire — Luminaires opératoires
DISFDIS stage
Warning for WD’s and CD’s
This document is not an ISO International Standard. It is distributed for review and comment. It is subject to change
without notice and may not be referred to as an International Standard.
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.
TThhiiss d drraftaft i iss s suubbmmiitttteded t too a pa pararallel vallel vootte e iinn I ISSOO,, C CEENN.

ISO/DISFDIS 9680:20252026(en)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
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Formatted: French (Switzerland)
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Formatted: German (Germany)
Formatted: German (Germany)
Published in Switzerland
Formatted: German (Germany)
Field Code Changed
iii
ISO/DISFDIS 9680:20252026(en)
Contents
Foreword . iv
Introduction . iv
Scope . iv
Normative references . iv
Terms and definitions . iv
Requirements . iv
Optical requirements . iv
Mechanical requirements. iv
Processing . iv
Electrical requirements . iv
Usability . iv
Sampling . iv
Testing . iv
General . iv
Visual inspection . iv
Optical tests . iv
Manufacturer's instructions . iv
Documents . iv
Instructions for use . iv
Technical description . iv
Check . iv
Packaging . iv
General . iv
Identification . iv
Marking . iv
Marking on the outside of operating lights . iv
Graphical symbols . iv
(informative) Additional information for retinal blue light hazard exposure test method . iv
(normative) Normalized absorbance of camphorquinone . iv
Bibliography . iv
Foreword . vi
Introduction . viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Requirements . 2
4.1 Optical requirements . 2
4.2 Mechanical requirements . 9
4.3 Processing. 10
4.4 Electrical requirements . 10
4.5 Usability . 10
5 Sampling . 10
iv
ISO/DISFDIS 9680:20252026(en)
6 Testing . 10
6.1 General. 10
6.2 Visual inspection . 10
6.3 Optical tests. 11
7 Manufacturer's instructions . 18
7.1 Documents . 18
7.2 Instructions for use . 18
7.3 Technical description . 19
8 Packaging . 19
8.1 General. 19
8.2 Identification . 19
9 Marking . 20
9.1 Marking on the outside of operating lights . 20
9.2 Graphical symbols . 20
Annex A (informative) Additional information for retinal blue light hazard exposure test
method . 21
Annex B (normative) Normalized absorbance of camphorquinone. 26
Bibliography . 30

v
ISO/DISFDIS 9680:20252026(en)
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO [had/had not] received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that this
may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 106, Dentistry, Subcommittee SC 6, Dental
equipment, in collaboration with the European Committee for Standardization (CEN) Technical Committee
CEN/TC 55, Dentistry, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This fifth edition cancels and replaces the fourth edition (ISO 9680:2021), which has been technically revised.
The main changes are as follows:
— Clause 4 “Classification” of the fourth edition has been deleted and subsequent clauses have been re-
numbered;.
— Clause 5 “Requirements and Recommendations” of the fourth edition has been adapted to Clause 4Clause
4 “Requirements” and technically updated;.
— Clause 6Clause 6 “Testing” has been technically updated;.
— ClauseSubclause 7.4 “Mechanical tests” of the fourth edition and all subclauses have been deleted;.
— Clause 9Clause 9 “Marking” has been technically updated;.
— Annex A “Transformation formulae” of the fourth edition has been deleted;.
— aA new informative Annex AAnnex A on “Additional information for retinal blue light hazard exposure test
method” has been added;.
— theThe normative and bibliographic references have been updated;.
vi
ISO/DISFDIS 9680:20252026(en)
— editorialEditorial updates have been made.
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.
vii
ISO/DISFDIS 9680:20252026(en)
Introduction
This document provides dentists and their staff with means to work with optimum visual ease and comfort in
all zones without adversely affecting their perception of colour or causing excessive fatigue or photobiological
injury.
In this document, the safety of an operating light is assessed in combination with its power supply. Such power
supplies may be incorporated in dental units or dental patient chairs.
Any item of equipment recommended by the manufacturer for use in conjunction with an operating light
should not render the equipment unsafe nor affect its qualities adversely.
[1]
IEC 60598-1IEC 60598-1 has been taken into account during the preparation of this document.
[2]
IEC 60601-1IEC 60601-1 specifies requirements pertaining to the basic safety and essential performance of
[1] [3]
medical electrical equipment and medical electrical systems. IEC 80601-2-60 IEC 80601-2-60 specifies
requirements pertaining to the basic safety and essential performance of dental units, dental patient chairs,
[1]
dental handpieces and dental operating lights. Requirements of IEC 60601-1 and IEC 80601-2-60 The
[2] [3]
requirements of IEC 60601-1 and IEC 80601-2-60 that are applicable to operating lights are not
duplicated in this document.
viii
ISO/DISFDIS 9680:20252026(en)
Dentistry — Operating lights
1 Scope
This document specifies requirements and test methods for operating lights used in dental treatment and
intended for illuminating the oral cavity of patients. It also contains specifications on the instructions for use,
marking and packaging.
This document applies to operating lights, irrespective of the technology of the light source.
This document excludes auxiliary light sources and those intended for patient contact, e.g. from dental
handpieces and dental headlamps, fibreoptic intraoral operating lightlights and also operating lights which
are specifically designed for use in oral surgery.
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 1942, Dentistry — Vocabulary
ISO 4073, Dentistry — Information system on the location of dental equipment in the working area of the oral
health care provider
ISO 9687, Dentistry — Graphical symbols for dental equipment
ISO 14971, Medical devices — Application of risk management to medical devices
ISO 15223-1, Medical devices — Symbols to be used with information to be supplied by the manufacturer — Part
1: General requirements
ISO 17664-1, Processing of health care products — Information to be provided by the medical device
manufacturer for the processing of medical devices — Part 1: Critical and semi-critical medical devices
ISO 17664-2, Processing of health care products — Information to be provided by the medical device
manufacturer for the processing of medical devices — Part 2: Non-critical medical devices
ISO/CIE 19476, Characterization of the performance of illuminance meters and luminance meters
ISO 21530, Dentistry — Materials used for dental equipment surfaces — Determination of resistance to chemical
disinfectants
IEC 60598-1, Luminaires - Part 1: General requirements and tests
IEC 60601-1:2005, Medical electrical equipment - Part 1: General requirements for basic safety and essential
performance
IEC 60601-1, Medical electrical equipment - Part 1: General requirements for basic safety and essential
performance
IEC 60601-1:2005/AMD1:2012, Amendment 1 - Medical electrical equipment - Part 1: General requirements for
basic safety and essential performance
ISO/DISFDIS 9680:20252026(en)
IEC 60601-1:2005/AMD2:2020, Amendment 2 - Medical electrical equipment - Part 1: General requirements for
basic safety and essential performance
IEC 62366-1, Medical devices — Part 1: Application of usability engineering to medical devices
IEC 62471, Photobiological safety of lamps and lamp systems
IEC 62471:2006, Photobiological safety of lamps and lamp systems
CIE 224, Colour Fidelity Index for accurate scientific use
CIE S 017 , ILV: International Lighting Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 , ISO 4073 , IEC 60598-1 , IEC
60601-1, CIE S 017 as well asand the following apply.
ISO and IEC maintain terminologicalterminology databases for use in standardization at the following
addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
Formatted: English (United States)
operating light
device for illuminating the oral cavity of a patient, which includes a fixed base and an adjustable arm
3.2
Formatted: English (United States)
light-activated restorative material
dental material intended for oral use that incorporates a monomer system, the polymerization of which is
activated by light
4 Requirements
4.1 Optical requirements
4.1.1 General
Optical requirements are specified at a distance of 700 mm. This standardized measurement distance enables
comparison of manufacturer specifications for different operating lights under the same conditions. For
clarity, the design of an operating light may be optimized for other distances and optical properties may be
reported by the manufacturer at additional distances at their discretion.
4.1.2 Adjustable level of illuminance
The level of illuminance shall be adjustable. The adjustment of illuminance may be either continuous or in
discrete levels.
The manufacturer shall provide specifications corresponding to the lowest and highest illuminance settings
for the maximum illuminance on a plane perpendicular to the optical axis at a distance of 700 mm from the
operating light. The manufacturer’s specification for illuminance at the highest illuminance setting shall be at
least 15 000 lx. The measured maximum illuminance values at the lowest and highest illuminance settings
shall be within 20% of their respective specifications.
ISO/DISFDIS 9680:20252026(en)
Test in accordance with 6.2 and 6.3.2.
The requirements of 4.1.2 do not apply to any operating mode(s) intended only for use while handling light-
activated restorative materials.
4.1.3 Illumination pattern
4.1.3.1 Illumination areas and illuminance levels
The illumination pattern shall be measured with the operating light adjusted to the maximum illuminance
level to determine the maximum illuminance, Ev,max, and the following iso-illuminance lines in accordance with
6.3.2: 0,90 × E , 0,75 × E , 0,50 × E , 0,10 × E and 1 200 lx.
v,max v,max v,max v,max
An area A is defined as the area bounded by the iso-illuminance line corresponding to 75 % of the maximum
illuminance. The border of area A shall be on or outside of an ellipse with a horizontal axis of 50 mm and a
vertical axis of 25 mm, in which the horizontal axis and vertical axis of the ellipse are aligned with the major
axis and minor axis of the illumination pattern, respectively (see Figure 1). The illuminance shall not be less
throughout the ellipse. Test in accordance with 6.3.2.
than 75 % of Ev,max
An area B is defined as the area bounded by the iso-illuminance line corresponding to 50 % of the maximum
illuminance. The border of area B shall be on or outside of an ellipse with a horizontal axis of 80 mm and a
vertical axis of 40 mm and with the same axes as the smaller ellipse associated with area A (see Figure 2 ).).
Test in accordance with 6.3.2.
Dimensions in millimetres
Key
A illumination area A
Figure 1
ISO/DISFDIS 9680:20252026(en)
Figure 1 — Example of illumination pattern which satisfies the requirement for area A
Dimensions in millimetres
Key
B illumination area B
Figure 2
Figure 2 — Example of illumination pattern which satisfies the requirement for area B
4.1.3.2 Illuminance uniformity
The illuminance shall decrease in intensity progressively and smoothly toward the pattern edge.
Test in accordance with 6.3.3.
ISO/DISFDIS 9680:20252026(en)
4.1.4 Illuminance in patient's eyes
An area C is defined as the area bounded by the iso-illuminance line corresponding to 90 % of the maximum
Formatted: Font: Not Italic
illuminance. The level of illuminance at all points on or above a horizontal line 60 mm above the uppermost
point of area C shall not be greater than 1200 lx (see Figure 3 ).).
Test in accordance with 6.3.4.
Dimensions in millimetres
Key
C illumination area C
Figure 3
ISO/DISFDIS 9680:20252026(en)
Figure 3 — Example of illumination pattern which satisfies the requirement for limiting illuminance
in the patient’s eyes
4.1.5 Chromatic uniformity
No perceptible chromatic variation (colour separation) of the light incident upon the measuring screen shall
be visible in area A and area B.
Test in accordance with 6.3.5.
4.1.6 Chromaticity and correlated colour temperature
Over the full range of illuminance levels, the correlated colour temperature shall be in the range of 3 600 K to
6 400 K within areas A and B of the illuminance pattern. D [the perpendicular distance in the 1960 CIE
uv
Uniform Chromaticity Scale (u, v) between the Planckian locus and the chromaticity coordinates of the
operating light] shall be within the range of −0,01 to +0,01.
For reference, the chromaticity limits in CIE (u, v) coordinates are depicted in Figure 4.
Preferably, whenWhen the operating light is adjusted to the maximum illuminance level, the correlated colour
temperature should be between 4 500 K and 6 400 K.
Test in accordance with 6.3.6.
The requirements of 4.1.6 do not apply to any operating modes intended only for use while handling light-
activated restorative materials.
ISO/DISFDIS 9680:20252026(en)
Key
v 1960 CIE Uniform Chromaticity Scale v-coordinate
Formatted: Font: Italic
u 1960 CIE Uniform Chromaticity Scale u-coordinate
Formatted: Font: Italic
Planckian locus
Chromaticity limits
Figure 4 — Chromaticity limits in CIE (u, v) coordinates
4.1.7 Shadow
The hard shadow of a disc with 20 mm diameter at a distance of 50 mm shall have a maximum diameter not
greater than 12 mm.
Test in accordance with 6.3.7.
ISO/DISFDIS 9680:20252026(en)
4.1.8 Colour fidelity
For general illumination of the oral cavity, the operating light shall have a general colour fidelity index, Rf, of
at least 85.
NOTE The importance of accurately assessing colour in dental diagnosis and treatment while using an operating
[4]
light supports specifying Rf as the measure for colour fidelity in this document even though CIE 224CIE 224 indicates
that R is not intended as a universal replacement for the general colour rendering index, R , at this time. The decision to
f a
specify Rf in this document was made in consultation with CIE.
Test in accordance with 6.3.8 .
The requirements of 4.1.8 do not apply to any operating modes intended only for use while handling light-
activated restorative materials.
4.1.9 Actinic UV hazard exposure for the skin and eye
Formatted: English (United States)
The risk group classification of the operating light for actinic ultraviolet hazard (E ) shall be Risk Group 1 or
s
lower, as specified in IEC 62471:2006, 6.1, when tested under the conditions specified in 6.3.9. Unless the
operating light is classified as an exempt group for actinic ultraviolet hazard, the permissible exposure
duration, tmax, per IEC 62471:2006 , 4.3.1 shall be calculated in accordance with 6.3.9.
Conformity with this requirement shall be verified either by documentation (e.g. test report by the light source
manufacturer) which verifies that all of the light sources used in the operating light do not emit in the
applicable wavelength range (200 nm to 400 nm), or by testing in accordance with 6.3.9.
4.1.10 Near-UV hazard exposure for the eye
Formatted: English (United States)
The risk group classification of the operating light for near-UV hazard (EUVA) shall be Risk Group 1 or lower, as
specified in IEC 62471:2006, 6.1, when tested under the conditions specified in 6.3.10.
Unless the operating light is classified as exempt group for near-UV hazard, the permissible exposure duration,
t , per IEC 62471:2006, 4.3.2 shall be calculated in accordance with 6.3.10.
max
Conformity with this requirement shall be verified either by documentation (e.g. A test report by the light
source manufacturer) which verifies that all of the light sources used in the operating light do not emit in the
applicable wavelength range (315 nm to 400 nm), or by testing in accordance with 6.3.10.
4.1.11 Retinal blue light hazard exposure
The risk group classification for retinal blue light hazard (L ) per IEC 62471:2006, 6.1 shall be Risk Group 1
B
or lower when tested under the conditions specified in 6.3.11.
Unless the operating light is classified as exempt group for retinal blue light hazard, the permissible exposure
duration, t , per IEC 62471:2006, 4.3.3 shall be calculated in accordance with 6.3.11.
max
Test in accordance with 6.3.11.
4.1.12 Single fault condition for photobiological safety
Formatted: English (United States)
Analysis under single fault condition shall be applied to the requirements for actinic UV exposure for skin and
eye (see 4.1.9 ),), near-UV exposure for the eye (see 4.1.10 )) and retinal blue light hazard exposure (see 4.1.11
).). The operating light shall be considered single fault safe (IEC 60601-1:2005, IEC 60601-
[5]
1:2005/AMD1:2012 & IEC 60601-1:2005/AMD2:2020,see IEC 60601-1 , 4.7) if the risk group classification
of the operating light does not exceed Risk Group 2 given inIECin IEC 62471:2006, 6.1 under single fault
condition.
ISO/DISFDIS 9680:20252026(en)
NOTE 1 A single fault condition, such as a short circuit or an open circuit of any component other than a component
with high-integrity characteristics or a software failure, can lead to a higher light emitting diode (LED) driving current,
increased light emission and a higher photobiological risk group classification.
NOTE 2 Analysis of the photobiological safety in single fault condition can be conducted based on the change in
illuminance under single fault condition relative to illuminance under normal conditions if the emission spectrum in
single fault condition is equivalent to the emission spectrum in normal conditions.
4.1.13 Irradiance (300 nm to 2 500 nm)
The irradiance over the wavelength range of 300 nm to 2 500 nm shall be ≤350 W/m at the maximum
illuminance level at a distance of 700 mm from the operating light.
Test in accordance with 6.3.12.
4.1.14 Compatibility with light-activated restorative materials
Formatted: English (United States)
If the operating light is equipped with a setting intended for use while handling light-activated restorative
materials, the maximum illuminance in this setting shall be at least 6 500 lx and the camphorquinone-
weighted irradiance shall be less than 3,0 W/m when tested under the conditions specified in 6.3.13. The
camphorquinone-weighted irradiance is the integral of the product of the operating light irradiance spectrum
and the normalized absorption spectrum of camphorquinone over the wavelength range of 400 nm to 515 nm
(see 6.3.13).
NOTE The photo-initiator systems of commercial dental restorative materials are currently based on one or more
of the following: camphorquinone, 1-phenyl-1,2 propanedione or acylphosphine oxides. Each of these photo-initiators
has a different absorbance spectrum. Since the absorbance spectrum of camphorquinone extends to longer wavelengths
than the other photo-initiators, the overlap with the emission spectrum of operating lights is greatest with
camphorquinone. Therefore, the camphorquinone absorbance spectrum is expected to represent the worst-case
challenge for evaluating possible effects of dental operating lights on light-activated restorative materials.
Test in accordance with 6.3.13.
4.2 Mechanical requirements
4.2.1 Operating controls
Operating controls shall be designed and located to minimize accidental activation. Graphical symbols for
operating controls and performance shall be in accordance with ISO 9687.
4.2.2 Rotational positioning
The operating light should be capable of rotating about the x-, y- and z-axes of the Cartesian coordinate system
to allow the operator maximum flexibility in positioning the operating light while preventing excessive
illuminance in the patient’s eyes.
EXAMPLE 1 Rotation of the operating light about the x-, y- and z-axes of the Cartesian coordinate system can be
achieved by three rotational pivot axes incorporated into the positioning arm of an operating light, even if the three
rotational pivot axes are not perpendicular to one another.
EXAMPLE 2 Rotation of the operating light about the x-, y- and z-axes of the Cartesian coordinate system can be
achieved by a ball-and-socket joint incorporated into the positioning arm of an operating light.
4.2.3 Stability after positioning
Operating lights should be free from apparent drift when positioned.
ISO/DISFDIS 9680:20252026(en)
4.2.4 Expelled parts
The operating light shall be designed to provide protection against the effects of the shattering of its light
source if it is possible for the light source to shatter. This requirement is not relevant for LED light sources.
The operating light shall be designed such that particles from a shattering light source cannot impair safety.
This shall be verified by appropriate risk analysis in accordance with ISO 14971.
4.3 Processing
All exterior touchable parts of the operating light shall be suitable for processing using the agents and methods
recommended by the manufacturer without deterioration of surfaces or labelling.
The manufacturer shall provide information on the processing for the operating light in accordance with ISO
17664-1 and ISO 17664-2, as applicable. Preferably, the handles should be sterilizable or capable of
accommodating reusable, sterilizable covers.
Testing of resistance against cleaning and disinfection shall be carried out in accordance with ISO 21530.
4.4 Electrical requirements
Operating lights shall be suitable for continuous operation. Conformity shall be verified by checking the
manufacturer’s documentation.
NOTE The designation of continuous operation is relevant to determining the applicability of certain electrical
[2] [1 [3
requirements of IEC 60601-1IEC 60601-1 and IEC 80601-2-60 ].
Formatted: Not Superscript/ Subscript
Field Code Changed
4.5 Usability
Usability evaluation shall be carried out following the process described in IEC 62366-1.
Testing shall be carried out in accordance with IEC 62366-1 .
5 Sampling
All type tests shall be made on one representative sample of the operating light.
6 Testing
6.1 General
All tests described in this document are type tests.
Testing shall be performed at an ambient temperature of (23 ± 2) °C. The relative humidity shall be between
30 % and 70 %.
All measurements of optical radiation shall be traceable to the international systemInternational System of
[2 [6
unitsUnits. See ISO/IEC 17025:2017 ], 6.5.2 for more information.
Formatted: Not Superscript/ Subscript
Field Code Changed
6.2 Visual inspection
Visual inspection shall be performed at normal visual acuity without magnification.
ISO/DISFDIS 9680:20252026(en)
6.3 Optical tests
6.3.1 Test set-up
Aim the light beam at a measuring screen, perpendicular to the optical axis, at a distance of 700 mm measured
from the external most forward part of the operating light from which light is emitted.
Adjust the controls for illumination during the tests at the setting of the maximum illuminance level unless
otherwise specified and operate until the irradiance and colour have stabilized, as determined by monitoring
the running average of the measurements, before collecting measurements for the tests specified in 6.3.2
through 6.3.13 unless otherwise specified.
Establish a rectangular coordinate system in the measurement plane with the origin of coordinates (i.e. the
coordinate axis intersection point) centrally placed in the zone of maximum illumination level and with the x-
axis parallel to the major axis of the illumination pattern. If there is a marked cut-off in the y-direction, take
this as the positive direction. If there is not a marked cut-off in the y-direction, arbitrarily select a direction to
be the positive direction.
For tests specifying visual assessment of the illuminance pattern, place a uniform, neutral, diffusely reflecting,
flat white screen in the measurement plane. For tests requiring instrumented measurements, place the
specified detector in the measurement plane unless otherwise specified.
Perform optical tests in a room where light from other sources and reflected light from room surfaces are
negligible.
If the operating light is designed to be used at a target distance other than 700 mm, testing shall also be
performed at the intended operating distance.
6.3.2 Level of illuminance and illuminance pattern
Formatted: English (United States)
Use the test set-up as described in 6.3.1 with the operating light adjusted to the maximum illuminance level.
Measure the illuminance levels with a photometer calibrated in accordance with ISO/CIE 19476 and having
an acceptance aperture with a diameter of 10 mm.
Moving the photometer within the measurement plane, make measurements at rectilinear coordinates not
more than 5 mm apart, such that all points within the illuminance pattern having an illuminance greater than
600 lx are measured.
A photometer that can indirectly record the illuminance distribution with one measurement [i.e. an imaging
luminance measurement device (ILMD)] may be used for this purpose. In such a case, the illuminance pattern
is normally projected onto a flat, uniform, diffusely reflecting screen positioned in the measurement plane and
the luminance distribution of the reflected light measured using the ILMD. The uniformity and directional
response of the reflectance characteristics of the screen shall be evaluated and either corrected for or taken
into account in the measurement uncertainties.
Record the measurements and their location. Determine the maximum illuminance, Ev,max. Use linear
interpolation of measurements to calculate and plot the following iso-illuminance lines specified in 4.1.3.1:
0,90 × E , 0,75 × E , 0,50 × E , 0,10 × E and 1 200 lx. Check whether the requirements
v,max v,max v,max v,max
corresponding to the highest illuminance setting given in 4.1.2 and 4.1.3.1 are fulfilled.
Repeat the measurements with the operating light adjusted to the minimum illuminance level. Check whether
the requirement corresponding to the lowest illuminance setting given in 4.1.2 is fulfilled (4.1.3.1 are fu is not
applicable with this setting).
ISO/DISFDIS 9680:20252026(en)
6.3.3 Illuminance uniformity
Use the test set-up as described in 6.3.1.
The requirement specified in 4.1.3.2 is fulfilled if no bright rings or bright spots outside of the central
maximum are visually apparent.
6.3.4 Illuminance in the patient’s eyes
Using the illuminance pattern data from 6.3.2, determine the coordinates of the uppermost point of area C (i.e.
Formatted: Font: Not Italic
the point along the iso-illuminance line corresponding to 90 % of the maximum illuminance which is farthest
from the horizontal axis in the positive y-direction). Plot a horizontal line 60 mm above the uppermost point
of area C. Check whether the illuminance at any point along or above the horizontal line exceeds 1200 lx (see
Formatted: Font: Not Italic
Figure 3).
To confirm whether there are any areas of brightness above the horizontal line, place a flat white screen in the
measurement plane. Observe whether there are areas of brightness above the horizontal line 60 mm above
the uppermost point of area C when viewed by a person with normal visual acuity at a distance of 50 cm to 75
cm. If any areas appear brighter than along the horizontal line 60 mm above the uppermost point of area C,
Formatted: Font: Not Italic
measure the illuminance in those areas using a calibrated photometer, as described above.in 6.3.2.
Record the measurements and their location. Check whether the requirement specified in 4.1.4 is fulfilled.
6.3.5 Chromatic uniformity
Adjust the room lighting to an illuminance level in the range of 1 % to 3 % of the maximum illuminance of the
operating light, measured at the centre of the measurement plane with a calibrated illuminance meter
oriented toward the room light source. Place a flat white screen in the measurement plane and illuminate it
with the operating light. Use three people with normal colour vision to observe whether there are any colour
non-uniformities within area A and area B when viewed at a distance of 50 cm to 75 cm. The normal colour
vision of the observers shall be verified within the past five years by at least one of the following:
— evaluation for colour vision by a medical practitioner or other appropriately trained person;
— the Ishihara colour vision test, either digitally or physically using colour assessment cards; or
1)
— the Hardy Rand and Rittler (HRR) Pseudoisochromatic Test, 4th Edition , colour vision test, either
digitally or physically using colour assessment cards .
Corrective untinted lenses may be worn.
6.3.6 Chromaticity and correlated colour temperature
Use the test set-up as described in 6.3.1 with the operating light set at maximum light output.
Determine the chromaticity coordinates at the point of maximum illuminance in the measurement plane, using
a tristimulus colourimeter or spectroradiometer and software with the capability to calculate correlated
colour temperature and D . Check whether the measured values for correlated colour temperature and D
uv uv
meet the requirements specified in 4.1.6.

1)
The HRR Pseudoisochromatic Test, 4th Edition is the trade name of a product supplied by Good-Lite Co, USA. This
information is given for the convenience of users of this document and does not constitute an endorsement by ISO of the
product named. Equivalent products may be used if they can be shown to lead to the same results.

ISO/DISFDIS 9680:20252026(en)
Repeat the test at each illuminance level of the operating light. If the operating light has continuous
illuminance adjustment or more than three illuminance levels, it is acceptable to test at the maximum
illuminance level, minimum illuminance level and one illuminance level at approximately the midpoint of the
illuminance range.
6.3.7 Shadow
Place the operating light to be tested at a distance of 700 mm from a measuring screen marked with a
rectangular coordinate system (see Figure 5), with the light beam normal to the measuring screen and the
illuminance pattern axes coincident with the measuring screen coordinates.
Place a support column outside the measurement area, supporting a 20 mm diameter disc that is 1-mm thick
and opaque. Position the disc parallel to the measuring screen with the centre of the disc on the axis normal
to the measuring screen coordinates at a distance of 50 mm from the screen. Measure the darkest shadow cast
on the target on the two main axes.
ISO/DISFDIS 9680:20252026(en)
Dimensions in millimetres
Key
1 operating light, or portion thereof capable of producing the illuminance pattern
2 pole
3 sliding ring for adjustment
4 screen
5 disc (opaque): 20 mm diameter × 1 mm thick
6 stem
ISO/DISFDIS 9680:20252026(en)
Figure 5 — Device for determination of shadow reduction
6.3.8 Colour fi
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