Quick facts
- An eye exam chart is a printed chart of optotypes used to measure visual acuity at a fixed test distance, usually 3 m, 4 m or 6 m.
- In the United States a visual acuity chart is a named Class I device at 21 CFR 886.1150, and the classification database lists it under product code HOX.
- In Canada a chart that does not touch the eye is a non-invasive device and falls to Class I under Rule 7(1) of the Medical Devices Regulations.
- The optotypes — the letters, the Landolt ring, the tumbling E — are defined by ISO 8596:2017, which also fixes the Snellen fraction notation.
- What moves the class is the claim, not the paper: a chart sold to screen or to test vision is a device; a decorative chart is not.
- The entries and rule text below were checked against the current eCFR text and the Regulations on 2026-10-07.
An eye exam chart is the printed sheet of letters, numbers or symbols a clinician uses to record how well a patient sees at a set distance. In the United States it is a named device with its own regulation number; in Canada it is a non-invasive device whose class depends on how it is described. This article compares the two rulebooks line by line, sets out the standard the optotypes have to follow, and explains why the same sheet of card can be a device on one shelf and a general supply on the next.
What is an eye exam chart?
The chart is a piece of printing on a matte surface, hung at a measured distance, with rows of optotypes that get smaller down the sheet. The patient reads down the rows and the smallest row read correctly is recorded as a fraction, such as 20/20 or 6/6. The sheet does not touch the patient, it is not sterile, and it carries no electronics. It is used in optometry lanes, ophthalmology clinics, paediatric offices, occupational health rooms and driving-assessment desks.
Because the chart is passive, the instinct is to treat it as stationery. Both regulators treat it as more than that, because the chart exists to produce a clinical measurement. The moment a product is intended to test or measure a patient, it stops being stationery in the eyes of the regulator and takes on the record-keeping that follows a device.
Why does the class follow the claim rather than the sheet?
A device is defined by its intended use. A printed card with no clinical purpose is a printed card. A printed card presented as a way to measure visual acuity is a device, because the maker is saying it performs a diagnostic function. The words on the carton, the instructions and the marketing are what record that intended use, and the intended use is what the rules act on. A buyer who needs a chart for clinical records should look for the claim, not the finish of the card.
How do Canada and the United States treat an eye exam chart?
The two countries reach a similar place from different machinery. The United States names the device; Canada classifies it by rule.
| Item | Canada | United States |
|---|---|---|
| Named entry | No entry names a visual acuity chart | 21 CFR 886.1150, Class I |
| Product code | Not applicable | HOX |
| Route to market | Manufacturer holds a device licence where the device is not Class I; a plain chart sits outside the licence-by-device path | Class I, generally exempt from premarket notification |
| Basis of the class | Intended use recorded for the device | The named entry it is filed under |
| Printed card, no claim | General supply | General supply |
| Card sold to screen vision | Device, Class I as a non-invasive device | Device, Class I under 886.1150 |
In Canada a chart that does not enter the body and does not touch the eye is a non-invasive device, and under Rule 7(1) of the Medical Devices Regulations "all other non-invasive devices are classified as Class I." Rule 7(2) lifts a non-invasive device to Class II only where it is intended to act as a calibrator, tester or quality-control support to another medical device, or to be connected to an active device. An acuity chart is read by a person, not wired to another device, so it stays at Class I.
In the United States the chart is filed under a named entry. 21 CFR 886.1150 covers a visual acuity chart, and the openFDA device classification API lists the entry at Class I under product code HOX. A Class I device of this kind reaches the market under general controls, and the entry is listed as exempt from premarket notification.
Which standard defines the optotypes?
The class table says what the chart is; the standard says how it must be built. ISO 8596:2017 covers ophthalmic optics and visual acuity testing, and it sets the standard and clinical optotypes and how they are presented. The standard describes the Landolt ring, the Snellen fraction notation and the scaling rules that keep the rows consistent, and it sits alongside the general requirements for ophthalmic instruments in ISO 15004-1:2020.
| Element | What the standard fixes | Why it matters at the lane |
|---|---|---|
| Optotype | Shape and stroke width of the letter or ring | A chart with the wrong stroke width records a different acuity |
| Notation | Snellen fraction and logMAR equivalents | Records have to be comparable between visits |
| Scaling | Size progression between rows | A missing row breaks the step between measurements |
| Distance | Test distance the sizes assume | A chart used off its marked distance misreads the result |
| Illumination | Light level for the test surface | A dim lane reads worse than the same eye in a bright one |
The practical consequence is that two charts of the same size and the same paper can produce different readings if one follows the optotype rules and the other does not. A clinician who keeps a printed record across visits is relying on the standard even when the chart never mentions it.
Which consumables does an eye lane restock alongside the chart?
The chart is one item on a bench that is restocked as a set. The smooth white exam table paper covers the headrest between patients so the lane is clean before the next test, and the double-tipped cotton swabs handle lid-margin prep where a test needs a clean surface. Where a clinic also takes a sample at the bench, the sterile graduated 90 mL specimen cups carry it away. Clinics that monitor their own steriliser pair the sterilization monitoring collection with the 24-hour monitoring five-pack trial. 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.
How is an eye exam chart used in practice?
The patient sits or stands at the marked distance, one eye is covered, and the clinician points to optotypes from the largest row downward. The smallest row the patient reads correctly, allowing a stated number of misses, becomes the acuity for that eye. The other eye is tested, then the result is recorded with the distance and whether the patient wore correction. Nothing about that sequence changes whether the chart touches the patient, which is why a chart is handled differently from an instrument that rests on the cornea.
Reading glasses and near-vision cards sit in the same family, and the difference between a distance chart and a near card is the working distance rather than the class. A lane that keeps both should keep the standard they follow with them, because a near card printed to a different rule will not be comparable with the distance result on the same form.
Sources
- 21 CFR 886.1150, Visual acuity chart
- openFDA device classification API
- Medical Devices Regulations, SOR/98-282, full text and Schedule 1
- Health Canada, medical devices
- ISO 8596:2017, ophthalmic optics, visual acuity testing
- ISO 15004-1:2020, ophthalmic instruments, general requirements
- ISO 13485:2016, medical devices quality management
- ISO 14971:2019, risk management of medical devices
- Standards Council of Canada
- CSA Group
- College of Optometrists of Ontario, standards of practice
- Opto, eye health library
- American Academy of Ophthalmology, eye health
- Public Health Ontario, infection prevention and control
- CCOHS, OSH answers
- US FDA, medical devices
- AAMI, standards and technical resources
- World Health Organization, blindness and visual impairment
Where a chart reading is recorded
A visual-acuity reading that is not written down cannot be compared with the next visit. The printable vision screening log is a blank sheet with columns for the patient, the eye, the distance used, whether correction was worn and the recorded acuity, so a change is visible against the previous test. The screening log generator on the same page sizes the form to the number of lanes and the distances a clinic runs. No account and no sign-up are needed to open either one.
Every lane and every chart differs. 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
- Snellen chart and eye test charts in Canada vs the US: which scale
- Eye chart in Canada vs the US: which optotype standard applies
- Visual acuity testing in Canada vs the US: which notation 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 an eye exam chart a regulated device?
Yes, where it is sold to test or screen vision. The United States names it at 21 CFR 886.1150 as a Class I device, and Canada treats it as a Class I non-invasive device under Rule 7(1) of the Medical Devices Regulations.
What is the difference between an eye chart and an eye exam chart?
The terms are used almost interchangeably. Both refer to a printed chart of optotypes read at a set distance; the phrase eye exam chart is simply more common in search and in clinic notes.
Does an eye chart need a licence in Canada?
A Class I device does not get a device licence of its own. The manufacturer holds an establishment licence and keeps the records the Regulations require, while a Class II device needs a licence under section 32 supported by a CAN/CSA-ISO 13485 quality management certificate.
Which standard covers the letters on the chart?
ISO 8596:2017 sets the standard and clinical optotypes and how they are presented, including the Landolt ring and the Snellen fraction notation, alongside the general ophthalmic instrument requirements in ISO 15004-1:2020.
Can a plain printed card avoid being a device?
Yes. A card with no clinical claim is a general supply. The class follows the intended use recorded for the product, so a chart sold as a decoration and a chart sold to measure acuity are described differently even when the printing is identical.
Does the test distance change the class?
No. Changing the working distance changes what the chart measures, not what it is. A near-vision card and a distance chart are both charts, and both are classified the same way.
Where can a clinic keep its acuity records?
The printable vision screening log at the compliance log centre has columns for the patient, eye, distance, correction and result, and the log generator on the same page sizes the sheet to the number of lanes a clinic runs.
Are the class rules the same for a near-vision card?
The rules are the same; only the working distance differs. A near card read at 40 cm is still a chart of optotypes and is classified the way a distance chart is.
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