Quick facts
- A pupil size chart is a printed card or ruler used to estimate pupil diameter by eye. A pupil gauge is the same idea in a sturdier form, and the instrument version is a pupillometer.
- United States: 21 CFR 886.1700 names the pupillometer and 21 CFR 886.1690 names the pupillograph, both Class I (general controls).
- The manual device carries a narrower burden than the powered one. The regulation exempts the manual pupillometer from the quality management system requirements except for records and complaint files, and that carve-out does not extend to the AC-powered device.
- Canada does not publish a named entry for a pupil gauge; devices are classified by definitions and Schedule 1 rules in the Medical Devices Regulations, SOR/98-282.
- A printed chart with no measuring claim is stationery, not a device in either market. The moment a product is presented as measuring pupil diameter, the instrument entries become relevant.
- Manufacturers still have to file in the United States when a device is "intended for a use different from the intended use of a legally marketed device" in its generic type, under 21 CFR 886.9.
A pupil size chart costs less than a coffee and is used in neurology observations, emergency triage and eye clinics. The regulatory question around it is smaller than the clinical one but easy to get wrong, because the answer depends on whether the object measures or merely illustrates: a printed card sits outside device rules, while a hand-held gauge and a powered pupillometer sit inside named entries with different obligations attached.
This article sets out what these tools do, how each country files them, why the manual and powered versions differ, what a pupil assessment documents, and which consumables the assessment consumes.
What is a pupil size chart used for?
Three jobs account for almost all clinical use.
Serial neurological observation. Pupil size and reactivity are recorded at fixed intervals after head injury, neurosurgery or sedation. Repeated measurement with the same tool is what makes the numbers comparable, which is why one gauge stays with the chart rather than in a drawer.
Acute assessment. In emergency triage, a gauge supports the documented description of a pupil that is dilated, pinpoint or unequal, and that description is what triggers escalation.
Optometric and ophthalmological examination. A gauge or pupillometer records pupil diameter before and after a dilating drop, and ISO 15004-1:2020 supplies the general requirements applicable to ophthalmic instruments of this kind.
One property is worth stating plainly: a chart is a visual reference, and any measurement it produces is an estimate. Where a clinician needs a number that can be trended against a previous reading, the instrument exists for that purpose.
How does the United States regulate a pupil gauge?
The United States names the instruments, and the two entries describe them precisely.
21 CFR 886.1690: "A pupillograph is an AC-powered device intended to measure the pupil of the eye by reflected light and record the responses of the pupil." Classification: Class I (general controls), exempt from premarket notification subject to the limitations in § 886.9.
21 CFR 886.1700: "A pupillometer is an AC-powered or manual device intended to measure by reflected light the width or diameter of the pupil of the eye." Classification: Class I (general controls).
Both entries describe measurement by reflected light. That phrase matters when a supplier is deciding whether a product falls inside a named entry or into general purpose laboratory equipment: a card printed with circles does neither, because it neither measures by reflected light nor records a response.
The third entry that touches this family is 21 CFR 886.5500, the digital therapy device for amblyopia, which shows how narrow the named entries are — the same part of the code deals with measurement, therapy and reading aids as separate lines.
Does Canada name a pupil gauge entry?
No. Canada classifies devices by rule rather than by named product line, so a supplier cannot look up "pupil gauge" in the way a US supplier looks up 886.1700. The Medical Devices Regulations, SOR/98-282 work from definitions and the Schedule 1 rules, and the class that results determines whether a device licence is required.
Two consequences follow for a buyer writing a specification.
- The claim decides the route. A measuring instrument sold to clinics is a device; the same sheet of card sold as an anatomical illustration is not presented as measuring anything.
- The class is derived, not quoted. Because there is no entry to read across, the classification argument is built from what the device does and where it contacts the patient, and it should be documented rather than assumed.
| Item | Canada | United States |
|---|---|---|
| Classification approach | Definitions plus Schedule 1 rules | Named device entry per product code |
| Named entry for a pupil gauge | None | 21 CFR 886.1700, pupillometer |
| Named entry for a recording instrument | None | 21 CFR 886.1690, pupillograph |
| Assigned class | Derived from the rules for the device as presented | Class I (general controls) for both entries |
| Premarket route | Device licence where the derived class requires it | Exempt from premarket notification, subject to § 886.9 |
| Position of a printed chart | Not presented as a measuring device | Not a device under either entry |
| Professional practice layer | Provincial college standards for optometry and medicine | State practice acts plus federal device rules |
CliniEco Medical holds Health Canada MDEL #35334 as an establishment, which is an authorisation to import and distribute devices in Canada. It is not a statement about any individual gauge or chart.
Why do the manual and powered devices differ?
Because the 2025 amendment to the pupillometer entry wrote a carve-out that reaches only the manual device.
The current text of 21 CFR 886.1700 states that both the AC-powered device and the manual device are exempt from premarket notification procedures, and then adds: "The manual device is also exempt from the current good manufacturing practice requirements of the quality management system regulation in part 820 of this chapter, except for requirements concerning records and complaint files under § 820.35 of this chapter." The citation history is [55 FR 48442, Nov. 20, 1990, as amended at 59 FR 63013, Dec. 7, 1994; 66 FR 38812, July 25, 2001; 90 FR 55991, Dec. 4, 2025].
Read carefully, that sentence does three things.
- It creates an asymmetry inside one entry. Two devices with the same intended use carry different quality system obligations purely because of how they are powered.
- It is not a full exemption. Records and complaint files under § 820.35 survive, along with the general controls that define Class I.
- It is stated for the manual device only. A powered pupil-measuring instrument stays inside the full part 820 framework.
The premarket side has its own limit. 21 CFR 886.9 explains that an exemption applies only to the extent that a device has "existing or reasonably foreseeable characteristics of commercially distributed devices within that generic type", and that a manufacturer must still submit a premarket notification where, for example, "the device is intended for a use different from the intended use of a legally marketed device in that generic type".
| Item | Canada | United States |
|---|---|---|
| Powered measurement instrument | Class derived under the rules; quality system duty applies by class and licence route | 21 CFR 886.1690 or 886.1700, Class I, quality system regulation applies |
| Manual gauge | Class derived under the rules | 21 CFR 886.1700, Class I; quality system regulation relief except records and complaint files |
| Premarket notification | Device licence route where required | Exempt, subject to § 886.9 limitations |
| Claim change | Can move the device to a different set of rules | Can remove the exemption, because the use differs from the generic type |
| Printed reference chart | Not a device as presented | Not within either named entry |
What does a pupil assessment document?
The tool is one line in a record, and the record is what protects the patient and the clinician.
A documented pupil assessment states the size in millimetres, the reactivity to light, whether the two sides are equal, and the time of the observation. Where a scale is used, the record names the scale, because a diameter read from one card and compared with a reading from another is not a comparison at all.
Two supports make that routine work in practice. The first is a light source that is consistent between observers, which is why penlights and the tool are stored together. The second is the form itself: the American Academy of Ophthalmology's patient information on the pupil covers the anatomy of a normal light response for the person at the receiving end, and AAO guidance on how often an eye examination is appropriate covers the recall side of an eye clinic's diary. Practices in Ontario also work within the standards published by the College of Optometrists of Ontario, and the Canadian Association of Optometrists maintains the patient-facing library.
Which consumables does a pupil assessment consume?
- Gloves on contact. Nitrile examination gloves are consumed whenever the clinician touches the patient's lids or a shared instrument handle.
- Single-use covers and paper. A gauge that is placed on the skin between patients is either disinfected or covered. Smooth examination table paper and disposable bed sheets carry the contact side of the examination.
- Eye and face protection. A dilated pupil makes the patient light-sensitive and a penlight examination is close work, so anti-fog face shields belong in the room.
- Documentation stock. The observation form, the gauge and the penlight are one kit, and the form is what turns a reading into a record.
Sources
- 21 CFR 886.1690, pupillograph
- 21 CFR 886.1700, pupillometer
- 21 CFR 886.9, limitations of exemptions
- 21 CFR 886.5500, digital therapy device for amblyopia
- 21 CFR 886.1405, ophthalmic trial lens set
- 21 CFR part 886, ophthalmic devices, eCFR current text
- 21 CFR part 820, quality management system regulation
- ISO 15004-1:2020, general requirements for ophthalmic instruments
- Medical Devices Regulations, SOR/98-282
- Health Canada, medical device guidance documents
- College of Optometrists of Ontario, standards of practice
- College of Optometrists of Ontario, infection control
- Canadian Association of Optometrists, eye health library
- Canadian Ophthalmological Society
- AAO, the pupil
- AAO, how often to have an eye exam
- AAO, infection control in the eye clinic
- CCOHS, personal protective equipment
- Public Health Ontario, infectious diseases
- WHO, blindness and visual impairment
Ordering for a clinic, laboratory or care home? Wholesale and multi-site ordering covers account setup and case pricing, and the B2B wholesale collection lists the lines stocked for institutional buyers. Clinics that also run an in-house sterilizer can start with the biological indicator 5-pack trial.
Related reading
- Eye charts in Canada vs the US: which acuity chart rules apply
- Amsler grid in Canada vs the US: which screening rules apply
- Visual field screening in Canada vs the US: which perimeter rules apply
- Eye shields in Canada vs the US: which device rules apply
- Comprehensive eye check-up in Canada vs the US: which exam interval
Frequently Asked Questions
Is a printed pupil size chart a medical device?
In the United States, the named entries describe instruments that measure the pupil by reflected light, and a printed card does neither. In Canada, a product is assessed on what it is presented as doing, so a chart sold as a visual reference is not presented as a measuring device. A gauge marketed to measure pupil diameter is a different proposition in both markets.
What is the difference between a pupillograph and a pupillometer?
21 CFR 886.1690 describes the pupillograph as an AC-powered device that measures the pupil by reflected light and records the responses, while 21 CFR 886.1700 describes the pupillometer as an AC-powered or manual device that measures pupil width or diameter. The recording function is what separates the two entries.
Why does the manual pupillometer have a lighter quality system burden?
Because the entry says so, and only for the manual device. The relief exempts the manual device from the quality management system requirements except for records and complaint files under § 820.35. The AC-powered device in the same entry does not receive that relief, and general controls still apply to both.
Does an exemption from premarket notification mean no filing is ever needed?
No. 21 CFR 886.9 limits exemptions to devices that have existing or reasonably foreseeable characteristics of commercially distributed devices in the generic type, and requires a premarket notification when a device is intended for a use different from the generic type's intended use.
Can a clinic use one gauge for every patient?
That is a local infection prevention decision rather than a regulatory one. What the record needs is the size in millimetres, the reactivity, the equality of the two sides, the time, and the tool used, because readings taken with different cards are not directly comparable.
Which standards apply to the powered instruments?
ISO 15004-1:2020 sets general requirements applicable to ophthalmic instruments, and the ISO 15004 series is the usual reference for a manufacturer documenting an instrument of this family. On the regulatory side, the United States applies part 820 to the powered device, while Canada derives the class from the rules.
CliniEco Medical supplies clinic and examination room consumables described in this article. Health Canada MDEL #35334. This article is written for clinic, laboratory and procurement professionals and is not clinical guidance; pupil assessment and documentation requirements belong to the treating practitioner.
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