Single Vision or Progressive? 4 Ways to Tell From Your Rx
Single Vision or Progressive? 4 Ways to Tell From Your Rx
Look at the ADD column on your prescription. If it carries a plus number, your lenses can be progressive or bifocal. If ADD is blank, they are single vision. Three quick checks confirm it: sweep the lens down a straight line, look for two tiny engravings, and read the lab sticker on the case.
That is the whole answer in four moves. The first one takes five seconds and rules out half the possibilities. The other three are physical — they tell you what the lens sitting on your desk actually is, which your prescription cannot do on its own.
Read one column
ADD, Add Power, NV or Near. Blank means single vision. A plus number means it could be a multifocal.
Sweep a straight edge
Straight all the way down is single vision. A sideways step is a bifocal. A gentle bend is a progressive.
Hunt the engravings
Two permanent laser marks 34 mm apart, standard on progressives. An add power engraved under the ear-side one settles it.
Read the paperwork
The lab order, the receipt or the sticker inside the case names the lens design outright.
Which column actually decides it?
A prescription has four or five columns and only one of them changes the answer. SPH, CYL and AXIS describe your distance correction. They are identical whether the lens ends up single vision, bifocal or progressive, so they tell you nothing about the design.
The column that decides is ADD. The American Academy of Ophthalmology describes it as the place where "any additional lens powers are written," and notes that people who would rather not carry a second pair for reading choose bifocals instead. That extra plus power is what a multifocal lens delivers in its lower half.
So the logic runs one way only. No ADD means the lens cannot be a progressive or a bifocal, because there is no near power to put in it. An ADD means it might be — and that is where the other three tests earn their keep.
Test 1: Is there an ADD or NV column?
Find the column and read it. Different clinics label it differently: ADD, Add Power, NV (near vision), Near, or simply Reading. Some prescriptions write a single value across both eyes, often followed by OU, which means both eyes together. The number is almost always a plus figure.
| Sample and eye | SPH | CYL | AXIS | ADD | What this can be made into |
|---|---|---|---|---|---|
| Sample A — right (OD) | −2.25 | −0.50 | 180 | blank | Single vision only |
| Sample A — left (OS) | −2.00 | — | — | blank | Single vision only |
| Sample B — right (OD) | −2.25 | −0.50 | 180 | +2.00 | Single vision, bifocal or progressive |
| Sample B — left (OS) | −2.00 | — | — | +2.00 | Single vision, bifocal or progressive |
Swipe the table sideways to see every column.
Sample A and Sample B have the same distance correction. Sample A can only become one thing. Sample B can become any of three things, and the prescription will never tell you which one the wearer actually chose. For that, put the paper down and pick up the glasses.
Careful with this one
A prescription written for contact lenses is a different document and often shows base curve and diameter instead of an ADD column. If you see BC and DIA on the page, you are holding a contact lens prescription, and it cannot be used to order glasses.
Test 2: Sweep the lens down a straight edge
This is the test that actually settles it. Hold one lens at arm's length, close one eye, and line it up with a straight vertical edge across the room — a door frame, a window frame, the side of a bookcase. Now move the lens slowly downward along that edge and watch what the edge does.
A single vision lens has one power everywhere, so the edge stays straight from the top of the lens to the bottom. A bifocal has a hard boundary, so the edge takes a visible sideways step where it crosses the segment. A progressive changes power gradually, so the edge bends instead of stepping, and the bottom corners of the lens go soft. The AAO puts that last effect plainly: progressive lenses "can also cause peripheral distortion when moving your eyes from side to side."
The sweep bench
Run three lenses down the same straight edges
One slider moves all three lenses down the same three vertical edges at once. Watch the edges, not the lenses.
Middle of the lens. The single vision edges are still perfectly straight. The bifocal segment has just come into view and the edges crossing it have jumped sideways. The progressive edges are starting to lean.
Do it with one lens only, and keep the glasses at arm's length rather than up against your eye. Close up, your own eye compensates and the effect disappears. At arm's length it is obvious within a second or two.
Test 3: Look for the two tiny engravings
Modern progressives carry two permanent laser marks, faint enough that most wearers never notice them. Finding a pair narrows the field quickly, but the marks alone do not close the case. What settles it is the tiny character engraved underneath the ear-side mark.
The Vision Council's lens marking guidelines, written in accordance with the ANSI Z80.1 and ISO 8980-2 standards, recommend two alignment reference marks with their centres 34 mm apart, sitting level with each other across the lens. One sits toward your nose, the other toward your ear. For a progressive they also call for "an indication of the add power of the lens, in diopters" directly below the ear-side mark, and the maker's name or trademark below the nose-side mark.
Those 34 mm marks are not unique to progressives. The same document provides for them on single vision lenses too — if alignment reference markings are present, it says, they should sit 34 mm apart in the same way, which is how a decentred or aspheric single vision lens gets positioned. So bare marks mean "progressive or a modern single vision design". Marks with an add power beneath the ear-side one mean progressive, full stop.
There is no universal way of writing that add: the guidelines call themselves recommendations rather than a mandate and set no digit convention, and their own diagram renders a +2.00 add as 200. Read whatever you find as a diopter figure, not a code.
Where to look
The engraving map on a right lens
Breathe on the lens and tilt it under a lamp. The marks are shallower than a fingerprint, so fog is what makes them show.
- Nose-side markBrand and design name engraved underneath. This is how a lab identifies which progressive you own.
- Ear-side markAdd power in diopters engraved underneath — the Vision Council diagram writes +2.00 as 200. Anything engraved here means progressive.
Find an add power under the ear-side mark and the question is closed: you own progressives. Find bare marks with nothing beneath them and the sweep test separates progressive from single vision in seconds. Find nothing at all after a proper look under a lamp, and check the other lens too — a scratched or heavily coated surface can hide a mark that is still there.
Test 4: Read the lab order or the case sticker
The least glamorous test is often the fastest. Whoever made the glasses wrote the design down somewhere, in words, without abbreviations.
- The receipt or lab order. Look for a line naming the design: single vision, SV, FT-28, flat top, or a progressive brand and design name.
- The sticker inside the case. Many labs put a small label on the case or the cleaning cloth sleeve listing lens type, material and coatings.
- The optical that dispensed them. They keep the order on file. One phone call, no guessing. If they were made here, call us at (780) 490-0090 and we will look it up.
If you are switching opticals and want the old pair identified before you order a new one, that is a normal request and takes a minute over the counter. Our details are on the contact page.
The four tests side by side
| Test | Single vision | Bifocal | Progressive | How conclusive |
|---|---|---|---|---|
| ADD or NV column | Blank | Plus number | Plus number | Rules out a multifocal. Cannot confirm one. |
| Sweep a straight edge | Edge stays straight | Edge steps sideways | Edge bends smoothly | Strong. Works in ten seconds with no tools. |
| Two laser engravings | Sometimes present on aspheric designs | Not needed; the segment is the reference | Present, 34 mm apart, add power below the ear-side one | Conclusive only if an add power is engraved under the ear-side mark. |
| Lab order or case sticker | Named in words | Named in words | Named in words | Conclusive when the paperwork survives. |
| Visible line across the lens | No | Yes | No | Separates bifocal from the other two instantly. |
Swipe the table sideways to see every column.
The prescription tells you what the lens could be. Only the lens tells you what it is.
Where bifocals fit, and what lenses cost
A bifocal splits the lens into two zones with a visible boundary: distance on top, reading below. A progressive ramps between them with no line at all, adding a usable middle distance on the way. That extra work is why the pricing differs. The AAO states that progressive lenses "are significantly more expensive than single or multi-focal glasses because of the extra time that goes into creating a lens with multiple prescriptions and no lines."
For an Alberta reference point, Eye-deology Vision Care reported in December 2025 that progressive eyeglass packages in the province typically begin at around $300 to $350, with mid-tier digital freeform progressives landing at $550 to $650 per pair plus a frame. Those are their figures for the market, not ours. Here is what we actually charge.
| Package | What is included | One pair | Two pairs |
|---|---|---|---|
| Single vision | Frame, single vision lenses, scratch-resistant coating | $99 | $159, mix and match frames |
| Progressive | Frame, premium progressive lenses, coating | $350 | $500, regularly $700 |
Swipe the table sideways to see every column.
Those two packages are what we publish. If your prescription needs something outside them, call (780) 490-0090 with the paper in front of you and we will price your exact numbers rather than guess at them. The full package list lives on the glasses deals page, and the progressive design itself is explained on our progressive lenses page.
One design is quicker than the other
Single vision lenses are far simpler to produce, which is why they can often be turned around the same day while a progressive is ordered in and surfaced. If speed matters more than having one pair do everything, see same-day glasses. Appointments are available and we will tell you the honest timeline for your prescription before you commit.
An ADD is a permission, not an instruction
This is the part most people get wrong, and it is worth ending on. An ADD number on your prescription does not mean you must wear progressives. It means your optometrist measured how much extra plus power you need to read comfortably. How that power reaches your eyes is your decision, not the prescription's.
The same +2.00 can be built three ways. Into a progressive, so one pair covers distance, computer and print. Into a bifocal, if you prefer a firm boundary and a wide reading zone. Or into a plain pair of single vision readers that live next to the book, while your distance glasses stay single vision. Plenty of people run two simple pairs and never touch a progressive — and with two single vision pairs at $159, that is a genuinely practical way to do it.
Read the ADD column as a fact about your eyes, not a verdict about your glasses. The four tests above tell you what you have got. What you buy next is still an open question.
Have the prescription in front of you
Call and we will price your exact prescription
Read us the SPH, CYL, AXIS and ADD and we will tell you what single vision and progressive each cost for your numbers — including whether your ADD is high enough that a progressive is worth it. No appointment needed to get a price. We are at 5035 Ellerslie Road SW, Edmonton, and we ship across Canada.
Prescription older than two years, or no expiry date on it? A current one is required before we can dispense. An adult eye exam is $99 and you can book an appointment online.
FAQ
How do I know if my prescription is single vision or progressive?
Look for a column labelled ADD, Add Power, NV or Near. If it carries a plus number, your prescription supports a progressive or a bifocal. If that column is blank, the prescription is single vision only. The prescription alone cannot tell you what your current glasses are, because an ADD can also be used to make single vision reading glasses. To confirm the lens you already own, sweep it down a straight edge and look for two tiny engravings.
What does ADD mean on my prescription?
ADD is the extra plus power built into the lower part of a lens so you can focus up close. The American Academy of Ophthalmology describes that column as the place where any additional lens powers are written, and notes that some people over 40 choose bifocals rather than carrying a second pair for reading. The same number can be built into a progressive, into a bifocal, or into a plain pair of single vision readers.
Does an ADD number mean I have to get progressive lenses?
No. An ADD is a permission, not an instruction. It records how much reading power your eyes need, and you decide how that power gets delivered. The same ADD can go into progressives, into bifocals, or into a dedicated pair of single vision reading glasses that stays on the desk. Plenty of people run two single vision pairs instead of one progressive pair.
How can I tell if my current glasses are progressives or bifocals?
Hold one lens at arm length and move it down a straight vertical edge such as a door frame. A bifocal makes the edge step sideways at a definite line across the lens. A progressive makes the edge bend gradually with no line anywhere, and the bottom corners of the lens go soft. A single vision lens keeps the edge straight from the top of the lens to the bottom.
Where are the engravings on progressive lenses?
Progressive lenses normally carry two permanent laser marks, one toward your nose and one toward your ear, with their centres 34 mm apart. The Vision Council lens marking guidelines, written in accordance with ANSI Z80.1 and ISO 8980-2, recommend that spacing. The marks alone are not proof of a progressive, because the same guidelines provide for 34 mm alignment marks on single vision lenses as well. What confirms a progressive is the add power in diopters engraved below the ear-side mark, with the brand below the nose-side mark. Breathe on the lens and tilt it under a lamp to find them.
Is a progressive lens more expensive than a bifocal?
Usually yes. The American Academy of Ophthalmology states that progressive lenses are significantly more expensive than single or multi-focal glasses because of the extra time that goes into creating a lens with multiple prescriptions and no lines. At Charm Optical the published packages are progressive at $350 for one pair and $500 for two pairs, and single vision at $99 for one pair and $159 for two pairs. Call us with your prescription and we will give you the number for your own lenses.
Can I use an old prescription with an ADD to order single vision glasses?
Yes, as long as the prescription is still valid. For distance-only lenses the lab uses the sphere, cylinder and axis and ignores the ADD. For single vision reading glasses the lab combines the ADD with the sphere instead. Either way the ADD does not force a progressive. Check the expiry date first, because an expired prescription cannot be dispensed.
How much do progressive glasses cost at Charm Optical?
A premium progressive package, meaning frame plus progressive lenses plus coating, is $350 for one pair and $500 for two pairs, a saving of $200 off the regular $700. For a market comparison, Eye-deology Vision Care reported in December 2025 that progressive eyeglass packages in Alberta typically begin at around $300 to $350. Call (780) 490-0090 and we will price your exact prescription.
Sources. American Academy of Ophthalmology, How to Read an Eyeglasses Prescription and Pros and Cons of Progressive Lenses. The Vision Council, Lens Marking Guidelines (ISO 8980-2, ANSI Z80.1). Eye-deology Vision Care, How much do progressive lenses cost in Alberta, December 2025. Charm Optical package prices verified against /pages/glasses-deal on 24 July 2026.