The main correction power
The main lens strength for each eye, how nearsighted or farsighted you are.
- Minus (−) = nearsighted, harder to see far away
- Plus (+) = farsighted, harder to see up close
- Usually in steps of 0.25
- 1. This is usually the first number on your slip. It tells us the overall power of your lens.
- 2. Higher numbers often mean thicker lenses. If yours is strong, ask us about thinner lens options in store.
- 3. If CYL and AXIS are blank or zero, single-vision lenses are usually all you need.
SPH −2.50 (mild nearsighted)
SPH +1.25 (mild farsighted)
Most everyday prescriptions sit between +6.00 and −12.00. Outside that range? Walk in. We'll confirm what's possible.
0.00 means that eye doesn't need distance correction, common for sun lenses or one eye that sees clearly.
The astigmatism correction
Corrects astigmatism, a second correction on top of SPH. Very common, and worth getting right.
- Usually a minus (−) value, copy the sign exactly
- Blank or 0.00 means no astigmatism
- Always paired with AXIS when filled in
- 1. Astigmatism just means your eye needs a slightly different correction in one direction. Nothing unusual.
- 2. CYL and AXIS work as a pair. If your slip has a CYL value, enter AXIS too.
- 3. Skipping CYL when your slip has a number can leave your vision feeling soft or strained.
CYL −0.75 AXIS 90
Most orders go up to around −4.00. Higher than that? Visit us. We'll check lens options before you commit.
Blank CYL? Leave CYL and AXIS empty when you order, don't enter zero unless your slip shows it.
The angle for astigmatism
The angle for astigmatism correction, only used when CYL has a value.
- A number from 1 to 180, no plus or minus
- Leave blank if CYL is zero or empty
- Copy the number exactly as written
- 1. AXIS tells us which angle to place your astigmatism correction, a number from 1 to 180.
- 2. Only matters when CYL has a value. No CYL? Leave AXIS blank.
- 3. Small changes between eye tests (like 89 vs 90) are normal. Always use what's on your current slip.
CYL −1.00 AXIS 180
If CYL is zero or blank, leave AXIS blank too, guessing can throw off your lenses.
Reading power for near vision
Extra reading power, built into progressive or Kriptok lenses for seeing up close.
- Common from your mid-40s onward
- Always a plus (+) value, often +0.75 to +3.00
- Blank or zero = single-vision only
- 1. ADD is the extra boost for reading and close work. It sits in the lower part of progressive or Kriptok lenses.
- 2. If your slip shows an ADD value, you'll likely want progressive or Kriptok, not plain single-vision.
- 3. Both eyes often share the same ADD, but copy exactly what your slip shows for each eye.
SPH −2.00 ADD +2.00
Most ADD values fall between +0.75 and +3.00.
Not sure which lens type you need? Walk in for a free eye test. We'll talk you through progressive, Kriptok, and single vision.
Distance between your pupils
The distance between your pupils in millimetres. We use this to centre your lenses properly.
- Single PD: one number (e.g. 63 mm)
- Dual PD: one per eye (e.g. 32 / 31)
- Measured during your eye test, yours is unique
- 1. PD centres each lens on your pupil. Get it wrong and your glasses can feel strained or slightly off, even with the right SPH.
- 2. It's usually printed on your prescription slip or receipt after an eye test.
- 3. Missing from your slip? Drop in. We measure it in a couple of minutes, free.
PD 63 (single)
PD 32 / 31 (per eye)
You'll need PD for prescription lens orders online. Frame-only or non-prescription orders don't.