Keep the sign, number and field name together when reading a contact lens prescription. +2.00 and −2.00 are different powers, 0.00 means no spherical power, and ADD is a separate near-correction parameter rather than an instruction to increase the Power dropdown yourself. This guide helps you recognize the labels and notice when an order needs clarification.
By KPOP2 Editorial. Prepared with AI assistance; source documents checked September 12, 2026. All numeric examples below are illustrations, not a prescription or a conversion method.
In this guide
Read the field before reading the number
The same-looking number can appear under different labels. A value beside SPH describes spherical power. A value beside CYL describes cylindrical power. ADD, where prescribed, relates to additional near correction. Removing the labels turns a meaningful record into a list of numbers that cannot safely be assigned to order options.
Start with the final contact lens prescription and keep the two eyes' information separate. On a typical record, OD identifies the right eye and OS the left. If your document uses different wording, retain that wording while asking for clarification. Do not infer the eye from where a number happens to appear in a cropped photograph.
The FDA's prescription overview explains that the record includes product information as well as power and fitting details. A note reading only “2.00” therefore does not identify the complete prescribed lens.
Keep plus, minus and zero distinct
Plus and minus are part of the power value, not decorative punctuation. In spherical lens descriptions, minus power is associated with correction for myopia and plus power with correction for hyperopia. You should still use the actual issued contact lens value rather than diagnosing your needs from how well you see at a particular distance.
Consider three illustrative dropdown entries: +2.00, −2.00 and 0.00. The first two share the same numerical magnitude but are not substitutes. The third is not an average or a lower-strength compromise. Selecting it changes the prescribed correction rather than solving an unavailable option.
Watch for a faint minus sign on a scan, especially near a table border. If the sign is unclear, obtain a clearer copy. Do not choose the version that happens to be available. The document checklist explains how to preserve readable labels, signs and decimal points.
Plano, often displayed as 0.00, means no spherical correction. A toric configuration can still involve other parameters, so do not translate plano into “no prescription information.” For U.S. cosmetic-lens requirements, see our zero-power guide.
Separate SPH, CYL and AXIS
SPH or Sphere is the spherical component expressed in diopters. CYL or Cylinder describes the cylindrical correction used for astigmatism. AXIS gives its prescribed orientation in degrees. They describe different aspects of a configuration and belong in their corresponding fields.
The manufacturer's 1-DAY ACUVUE MOIST patient guide lists lens-power, cylinder and axis abbreviations separately from the near-ADD labels used for its multifocal version. This is a useful example of why the product version determines which parameters are relevant.
If a toric prescription has a particular sphere, cylinder and axis, finding the sphere alone on another product page does not establish a matching order. Keep the combination together. Our toric ordering checklist handles the left-and-right selection process in detail.
Do not transpose cylinder notation or convert a glasses prescription yourself to make the entries fit a store form. Ask the prescriber to clarify the contact lens record if its format does not correspond to the intended product. A dropdown is an ordering interface, not a clinical calculator.
Understand ADD without adding it to Power
ADD identifies additional near correction in an applicable prescription or lens design. It is not the same field as distance sphere. Manufacturers can express multifocal add options numerically or through product-specific categories. The MOIST guide, for example, distinguishes Low, Mid and High near-add labels for its multifocal product.
Do not assume that one brand's Low category equals another brand's Low category. The CooperVision product reference guide presents multifocal sphere and ADD as separate specifications, with designs and options that depend on the named lens. These examples explain terminology; they are not a recommendation to switch products.
If an illustrative prescription shows SPH −2.00 and ADD +1.50, do not calculate a new Power value by adding the two and then order an ordinary single-vision colored lens. That arithmetic does not recreate the prescribed multifocal design. Keep both original fields and discuss the desired colored product with your eye care professional.
Near-vision difficulty also should not be reduced to “I need plus-colored contacts.” Presbyopia and hyperopia are different concepts, and the appropriate correction depends on assessment. A product name containing a color or the word “natural” says nothing about whether it provides the near correction you need.
Check what the exact product actually offers
A power range gives endpoints, while the selectable options show the configurations presented for ordering. Do not assume that every quarter-diopter step between the endpoints exists. Keep the exact shade, replacement version and product type selected while checking its options.
Use a short comparison with three entries: what the prescription says, what the product page offers, and what remains unresolved. For example, write “required ADD not shown” rather than leaving ADD out of the record. A missing field can be the important finding.
- Sign mismatch: confirm the source value; do not replace plus with minus.
- Step missing: ask about the exact value; do not round to a nearby option.
- CYL or AXIS missing: verify whether you are viewing the correct toric product.
- ADD missing: do not assume the lens provides the prescribed multifocal correction.
- Product name different: seek professional clarification about the proposed product.
The useful next question for support is specific: “Does this exact product have the configuration shown on my contact lens prescription?” If the question is whether a different configuration is suitable for your eyes, direct it to the prescriber.
Keep an exact order record
Before checkout, compare each eye's selected options with the original prescription rather than with a note copied from memory. Read labels and values together one more time. This is especially helpful after changing a shade or product version, because a selection made for an earlier candidate may no longer apply.
Keep the product's complete name and the relevant document together in your private records. An old order is useful for identifying what you bought, but a new prescription can change what you should order next. Do not let a saved cart silently become the source of current prescription values.
If you need help presenting the document, follow KPOP2's verification instructions. For packaging and quantity questions after the correct configuration is established, return to Lens 101.
Common power-label questions
Are +2.00 and −2.00 the same strength?
They have the same magnitude but opposite signs and are different optical powers. Use the prescribed signed value.
Does 0.00 mean no fitting is needed?
No. Plano describes spherical power, not whether a lens fits or whether a prescription is required.
Can I leave CYL out if the sphere matches?
Do not omit prescribed parameters. Confirm the complete configuration for the exact product.
Is AXIS another power?
No. It describes orientation in degrees and should remain in the axis field.
Can I add ADD to SPH and buy that result?
No. That calculation does not recreate a prescribed multifocal lens design.
Does every colored contact lens have an ADD option?
Do not assume so. Check the exact model and prescription rather than treating cosmetic color as a correction type.
Does a range guarantee every value is available?
No. Check the actual options and ask about a missing configuration instead of rounding.
What should I do if the handwriting is unclear?
Request clarification from the issuer. Preserve the original document and do not invent a value.
