Quick facts
- An over-the-counter reading glass is a magnifying spectacle, filed in the United States under 21 CFR 886.5840 at Class I.
- A vision chart or reading card used with it is a separate entry, 21 CFR 886.1150, also Class I.
- A strength chart is a selection aid for a shelf; it is not a prescription and it does not carry sphere, cylinder, axis or pupillary distance.
- In Canada a non-prescription magnifying spectacle is a Class I device under Rule 7(1) of the Medical Devices Regulations; the sale of eyewear is regulated by the province.
- The class does not decide the power. ISO 8980-1 fixes how a spectacle lens power is stated, and a chart is only useful if it matches that scheme.
- The entries and rule text quoted here were checked against the openFDA device classification API and the Regulations on 2026-10-06.
A reading glasses strength chart is a printed table that maps a dioptre value, usually from about +1.00 to +3.00 D, to a shelf label so a shopper can pick a ready-made reader. It is used by opticians, by pharmacies and by clinics that hand out a reader while a prescription is being made. The important thing to know is that the chart and the prescription answer two different questions.
What is a reading glasses strength chart?
A strength chart answers one question: which magnifying power lets an adult read a near card comfortably. The reader it points to has the same power in both eyes, a single value, and no cylinder or axis. Charts are commonly printed next to a near card that the shopper holds at reading distance, and the pair is used to choose from the shelf.
A prescription answers a different question. It records the power needed for each eye separately, the astigmatism correction (cylinder and axis), the reading addition, and the pupillary distance. A chart cannot capture any of those, which is why a reader from a shelf and a prescribed pair are not interchangeable documents.
How do Canada and the United States classify a reader and its chart?
The two countries take the same route to the class, from different rules.
| Item | Canada | United States |
|---|---|---|
| Ready-made reader | Class I, non-invasive device under Rule 7(1) | Class I, 21 CFR 886.5840 |
| Spectacle frame | Accessory to the lens | Class I, 21 CFR 886.5842 |
| Near card or vision chart | Class I, or a simple printed aid | Class I, 21 CFR 886.1150 |
| Prescription eyewear | Regulated by the province; a device if it corrects vision | Marketed under the spectacle rules |
| Who may fit or dispense | The provincial college for opticians and optometrists | State-level opticianry rules |
In the United States a magnifying spectacle is a named Class I entry, and a pair filed under that entry is a low-risk device. In Canada a pair of readers is a non-invasive device and Rule 7(1) of the Regulations places all other non-invasive devices in Class I. A Class I device is not licensed device by device; the manufacturer keeps an establishment licence and the records the Regulations require.
That is the part that surprises a buyer. The class is low on both sides, yet the act of dispensing a pair of glasses — even a reader — is a provincial or state matter rather than a device matter. An optician in Ontario works under the College of Opticians of Ontario, and an optometrist works under the College of Optometrists of Ontario.
Why is a strength chart not a prescription?
Because the chart is a shelf aid and the prescription is a measurement of an eye. ISO 8980-1 sets the tolerances and the notation for finished single-vision lens powers, and a reader's printed power has to line up with that notation to mean anything. A chart that shows "+2.00" is telling a shopper what the lens power is, not what the eye needs.
The gap shows up in two places. The first is anisometropia, where the two eyes need different powers; a reader cannot supply that because both lenses are equal. The second is astigmatism; a reader has no cylinder, so a shopper with significant astigmatism will still not see sharply. A chart that sends that shopper to a shelf value is not wrong, but it is incomplete.
Which standard fixes how a lens power is stated?
The power statement itself is standardised, and that is what keeps a chart honest. ISO 8980-1 and ISO 8980-2 cover finished single-vision and progressive lenses respectively, and ANSI Z80.1 sets the prescription requirements used in the United States. A supplier that prints a chart should be able to say which notation it follows, because a chart in one notation read as another is worse than no chart at all.
For a clinic the practical step is to keep the chart and the near card together and to say, in plain words, that the chart picks a shelf reader and not a spectacle prescription. That single sentence removes most of the confusion a shopper brings to the shelf.
What do the two rulebooks actually say?
The two texts are short, and the difference between them is the point of this article.
| Rule or entry | Wording in the source | Effect on a reader and its chart |
|---|---|---|
| 21 CFR 886.5840, US | Spectacle, magnifying | Named Class I entry |
| 21 CFR 886.5842, US | Frame, spectacle | Class I accessory |
| 21 CFR 886.1150, US | Chart, visual acuity | Class I chart |
| Rule 7(1), Canada | all other non-invasive devices are classified as Class I | Class I reader |
| Rule 3(a), Canada | denture materials and orthodontic appliances … Class II | Does not apply |
Read together, the five lines explain why a supplier cannot raise or lower the class by calling a reader a prescription device. A lens described as a reading aid while it is sold from a shelf is described against the text, not against the shelf.
Which consumables does a dispensing room restock?
An optical room runs on the same bench supplies as any other room. The smooth white exam table paper covers the fitting bench between patients, and the double-tipped cotton swabs handle the routine wipe-down of a trial frame. A practice that also 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.
Which power range does a shelf reader cover?
A ready-made reader is sold in steps of a quarter dioptre, and the shelf range usually runs from about +0.75 D to +3.00 D. Below that range a shopper does not need a magnifier, and above it the value is large enough that the shelf is no longer a safe substitute for a refraction. The chart should print the range it covers, because a shopper who cannot see at the printed end of the scale needs an optometric assessment rather than the next step up.
The range is a shelf fact rather than a regulatory one, and the two are easy to confuse. A supplier is free to print a chart as long as the powers on it match the notation in ISO 8980-1; what the supplier may not do is present a shelf power as a prescription. A clinic that says so in one line — the chart picks a reader, and the optometrist writes the prescription — removes most of the confusion a shopper brings to the shelf.
Sources
- 21 CFR 886.5840, Spectacle, magnifying
- 21 CFR 886.5842, Frame, spectacle
- 21 CFR 886.1150, Chart, visual acuity
- 21 CFR 886.1650, Prism, bar, ophthalmic
- Medical Devices Regulations, SOR/98-282, full text
- openFDA device classification API
- ISO 8980-1:2017, finished single-vision spectacle lenses
- ISO 8980-2:2017, finished progressive-power spectacle lenses
- ANSI Z80.1, ophthalmics, prescription requirements
- ISO 13485:2016, medical devices quality management
- Health Canada, medical devices guidance
- College of Opticians of Ontario
- College of Optometrists of Ontario, standards of practice
- Opto, eye health library
- American Academy of Ophthalmology, eye health
- Standards Council of Canada
- CCOHS, OSH answers
- Public Health Ontario, laboratory services test index
A count of how many readers a room hands out is a count that is hard to rebuild later. The printable reader dispensed log is a blank form with columns for the power, the quantity and the date handed over, so a shortfall is visible on the day. The reader log generator on the same page sizes the form to the number of fitting rooms a practice runs. No account and no sign-up are needed to open either one.
Every optical setup 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
- Eye Pads in Canada vs the US: Ophthalmic Dressing Pads
- Eye Shields in Canada vs the US: Which Device Rules Apply?
- Near Vision Reading Cards in Canada vs the US
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 pair of ready-made reading glasses a Class I device in the United States?
Yes. A magnifying spectacle is a named Class I entry at 21 CFR 886.5840, and a near card or chart is a separate Class I entry at 21 CFR 886.1150.
How does Canada classify the same reader?
In Canada a non-prescription magnifying spectacle is a non-invasive device, and Rule 7(1) of the Medical Devices Regulations places all other non-invasive devices in Class I. The sale of eyewear is regulated by the province, not by the class.
Can a strength chart be used as a prescription?
No. A chart carries a single power, while a prescription records the power for each eye, the cylinder and axis, the addition and the pupillary distance. A reader cannot supply unequal powers or an astigmatism correction.
Which standard decides how a lens power is written?
ISO 8980-1 covers finished single-vision lenses and ISO 8980-2 covers progressive lenses, and ANSI Z80.1 sets the prescription requirements used in the United States. A chart should state which notation it follows.
Why do both lenses in a reader have the same power?
Because a ready-made reader is a magnifier, not a correction. It is made in equal powers so it can sit on a shelf; a shopper whose two eyes need different powers needs a prescription instead.
Is a value above +3.00 D still a reader?
Once the required power passes the range a reader can carry, the shelf value stops being a way to avoid a prescription. A clinic that reaches the end of the chart should move the patient to a full refraction rather than to a higher magnifier.
What does the class change for a supplier?
In Canada a Class I device sits under an establishment licence and records rather than a device licence, while a Class II device needs a licence under section 32 supported by an ISO 13485 certificate. In the United States a Class I entry reaches the market without premarket notification where the entry is exempt under 21 CFR 886.9.
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