Quick facts
- A Schirmer tear test strip is a named Class I device in the United States at 21 CFR 886.1800.
- Canada names no tear test strip. A strip that touches the surface of the eye is an invasive device, and Rule 2(1) of the Medical Devices Regulations places it in Class II.
- The same strip is therefore Class I in the United States and Class II in Canada — the class follows the route, not the brand.
- A strip intended to stay in contact with the eye for 30 consecutive days or more moves to Class III under Rule 2(3).
- A Schirmer test measures tear production over a fixed interval; it is a diagnostic aid, not a treatment.
- The regulation text quoted here is current to 2026-09-21 and was last amended on 2026-06-17.
A Schirmer tear test strip is a small paper strip placed under the lower eyelid to measure how much the eye waters in a set time. It is used when a clinician wants to separate a dry eye that makes too little tear from one that loses tear too fast. The two countries do not sort that strip the same way, and the difference is not cosmetic.
What is a Schirmer tear test strip?
It is a strip of absorbent paper, usually 5 mm wide and notched at one end so it can hook over the lower lid without touching the cornea. The clinician places the notched end in the lower conjunctival sac and leaves it in place for a fixed interval, most often five minutes, then reads how many millimetres of the strip the tear has wetted.
The strip is a physical measuring scale, not an electronic sensor. Because it is read by eye against a printed scale, the result depends on the paper, the interval and the ambient conditions, which is why a laboratory or a clinic that repeats the test works to a written procedure. Nothing on the strip treats the eye; it only records how far the tear travels.
That single fact — a paper object held against the surface of the eye — is what decides its class in Canada, and it is the reason a strip that looks identical to a US product carries a different class north of the border.
How do Canada and the United States classify a Schirmer tear test strip?
The strip is Class I on one side of the border and Class II on the other, because the two rulebooks sort the same object by two different ideas.
| Item | Canada | United States |
|---|---|---|
| Schirmer tear test strip | Class II by Rule 2(1) | Class I, 21 CFR 886.1800 |
| Basis named in the rulebook | Rule and intended use | Device entry and product code (KYD) |
| What decides the class | Whether it touches the surface of the eye | Which named entry it is filed under |
| Strip left in contact for 30 days or more | Class III by Rule 2(3) | Still the same named entry |
| Result of the difference | A licence and a quality-system certificate are required | A Class I entry with general controls |
In the United States the strip is a named entry at 21 CFR 886.1800, and a product filed under that entry is Class I. In Canada no entry names a tear test strip. The Regulations instead define an invasive device as one that is intended to come into contact with the surface of the eye or to penetrate the body, and Rule 2(1) classifies every invasive device that penetrates a body orifice or touches the surface of the eye as Class II.
A strip does not penetrate anything and it is not absorbed, so the absorbing subrules do not apply. What applies is contact with the surface of the eye, and that single contact is enough to put the strip in Class II.
Which licence and records differ between Canada and the United States?
For a supplier the class is not a label; it decides which paperwork has to exist before the strip can be sold.
In the United States a Class I device that is not exempt is placed on the market through the premarket notification route, and the manufacturer keeps the design and labelling records that the entry requires. In Canada a Class II device needs a medical device licence before sale, and a licence application is supported by a quality-system certificate against ISO 13485, together with the labelling and evidence the Regulations set out. A US-based supplier that treats the strip as a Class I accessory and ships it into Canada without a licence is holding a Class II device with no licence.
That is the practical cost of the difference. The strip itself is unchanged. What changes is that the Canadian pathway expects a licensed Class II device, an ISO 13485 certificate and records kept for the interval the Regulations require, while the US pathway for the same item rides on a Class I entry.
Why does a strip that touches the eye change class in Canada?
Because the rulebook classifies by contact and by duration, not by how simple the object looks.
Rule 2(1) sets the base class at II for any invasive device that touches the surface of the eye. Rule 2(2) steps a device down to Class I only when it is placed in the oral or nasal cavity as far as the pharynx, or in the ear canal up to the ear drum — none of which is the eye. Rule 2(3) steps a device up to Class III when it is normally intended to remain in the body or in contact with the surface of the eye for at least 30 consecutive days. Rule 2(4) covers a device that is presented as preventing the transmission of infectious agents during sexual activity, which is not this product.
A Schirmer strip sits in the first of those bands. It touches the eye and it is withdrawn within minutes, so the base rule gives Class II and neither the step-down nor the step-up applies. The design rule is easy to state: read the contact, then read the duration, then read the exceptions. A product that is described as staying on the eye for a month is no longer a Class II strip.
Which consumables does a dry-eye assessment room restock?
A clinic that runs tear testing runs on the same bench supplies as any other examination lane. The smooth white exam table paper covers the headrest between patients, and the double-tipped cotton swabs handle the lid margin prep that comes before a strip is placed. Where samples are also collected at the bench, the sterile graduated 90 mL specimen cups carry them away, and a clinic that monitors its own steriliser pairs the sterilization monitoring collection with the 24-hour monitoring five-pack trial. Clinics and multi-site groups ordering at case level use the wholesale ordering page, and the B2B wholesale collection lists the lines held for institutional buyers. Reselling? become a distributor.
What do the two rulebooks actually say?
The two texts are short, and the difference between them is the whole point of this article.
| Rule or entry | Verbatim wording | Effect on a tear test strip |
|---|---|---|
| Rule 2(1), Canada | all invasive devices that penetrate the body through a body orifice or that come into contact with the surface of the eye are classified as Class II | The strip touches the eye, so Class II |
| Rule 2(2), Canada | placed in the oral or nasal cavities as far as the pharynx or in the ear canal up to the ear drum is classified as Class I | Does not apply to the eye |
| Rule 2(3), Canada | remain in the body or in contact with the surface of the eye for at least 30 consecutive days is classified as Class III | Applies only to a long-wear product |
| 21 CFR 886.1800, US | Schirmer strip | Named Class I entry |
| Rule 7(1), Canada | all other non-invasive devices are classified as Class I | Does not apply, because the strip is invasive |
Read together, the four lines explain why a supplier cannot move the class by relabelling. A strip described as non-invasive while it is drawn across the surface of the eye is described against the text, not against the product.
Sources
- 21 CFR 886.1800, Schirmer strip
- 21 CFR 886.1270, exophthalmometer
- 21 CFR 886.1040, ocular esthesiometer
- 21 CFR 886.1150, visual acuity chart
- 21 CFR 886.1170, colour vision tester
- Medical Devices Regulations, SOR/98-282, full text
- openFDA device classification API
- ISO 15004-1:2020, ophthalmic instruments, general requirements
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, risk management for medical devices
- College of Optometrists of Ontario, standards of practice
- Opto, eye health library
- American Academy of Ophthalmology, eye health
- Public Health Ontario, laboratory services test index
- CCOHS, OSH answers
- Canadian Dental Association
- Royal College of Dental Surgeons of Ontario
- CLSI, clinical and laboratory standards
- Government of Canada, medical devices guidance
- Standards Council of Canada
A tear test that is not written down is a tear test that cannot be repeated. The printable dry-eye assessment log is a blank sheet with columns for the patient, the time of day, the interval used and the wetting in millimetres, so a follow-up test repeats the conditions rather than the guesswork. The assessment record generator on the same page sizes the sheet to the number of lanes and the intervals a clinic runs. No account and no sign-up are needed to open either one.
Every clinic layout is different. Ask a compliance specialist and you will get a written answer specific to your equipment and province, with the regulation or standard it is based on cited.
Related reading
- Artificial Tears in Canada vs the US: Which Rules Apply?
- Conjunctivitis Eye Drops in Canada vs the US: Which Rules Apply?
- Ophthalmic Refractometers in Canada vs the US: Which Class Applies?
CliniEco Medical supplies eye care, laboratory and dental consumables of the kind described in this article. MDEL #35334. This article is written for optometry, laboratory and procurement professionals and is not legal advice; the class of a device and the records kept by a clinic belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
Is a Schirmer tear test strip a Class I device in the United States?
Yes. A Schirmer strip is a named Class I entry at 21 CFR 886.1800, filed under product code KYD.
How does Canada classify the same strip?
Canada names no tear test strip. Because the strip comes into contact with the surface of the eye it is an invasive device, and Rule 2(1) of the Medical Devices Regulations places it in Class II.
Does the strip have to stay on the eye to stay Class II?
No. The base class is set by contact with the surface of the eye, which gives Class II for a strip used and removed within minutes. A strip intended to remain in contact with the eye for at least 30 consecutive days moves to Class III under Rule 2(3).
Why does the same product carry two classes?
Because each country sorts it by a different idea. The United States sorts the strip by its named entry, and Canada sorts it by the contact it makes and the time it stays in place.
What does the class change for a supplier?
A Class II device sold in Canada needs a medical device licence supported by a quality-system certificate against ISO 13485. A Class I entry in the United States rides on a different, lighter pathway.
Is a Schirmer strip a treatment?
No. It is a measuring aid used to record tear production over a fixed interval. The strip records the result; the clinician decides what follows.
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