We are often asked about frame measurements, P.D. (pupillary distance).
We are committed to patient choice; if the PD (or any other) measurement is available on your file from an exam or glasses purchase, we would be happy to provide you with a copy of that information upon request.
What is a PD?
PD (pupillary distance) determines where to place the optical center (horizontal position) of prescription lenses into a frame.
For a correct lens eyeglass fitting, additional measurements are also required:
- optical center height (vertical position)
- pantoscopic angle
- vertex distance
- frame wrap
We take the additional measurements only when you are wearing the actual frame as it varies depending on the frame.
Will you measure my PD?
For existing patients, we likely have your P.D. on file and will provide it on request.
When pre-testing for an exam, a binocular P.D. measurement is taken by one of the pre-test devices. This number is normally stored on your exam record and will be provided upon request. Please contact the location where your exam was completed.
What if I am not a customer?
Sorry, we do not offer a standalone “PD measurement” service. Please contact the retailer where you are purchasing your glasses to have the measurement done or for instructions on how to measure.
* In British Columbia only, the P.D. is normally included on the spectacle prescription. In other provinces it is available on request.
Optikam – the advanced measurement tool
A basic P.D. is not enough for a perfect eyewear result. This is why we offer an advanced iPad-based device called the Optikam to digitally take 6+ position-of-wear measurements.
Because we are measuring the actual frame you are purchasing, we can adjust your prescription lenses for exactly how the frame affects that prescription.
Measured in 0.1mm increments the Optikam is up to 5X more accurate than conventional measurement techniques.
Then we manufacture prescription lenses taking into account:
- The doctor’s prescription, and
- How the frame fits on your face
Optikam measurements (compared to a manual measurement) are taken to improve optics, accuracy and comfort of the resulting prescription eyewear. We do not recommend ordering lenses without taking these additional measurements into account.
We offer the Optikam process exclusively to those purchasing eyeglass lenses at our clinic.
What measurements do we take?
From ONE picture, the Optikam will measure:
- Monocular Pupillary Distance (P.D.)
- Multifocal Seg Heights
- Optical center (O.C. height)
- Pantiscopic Tilt (panto)
- Vertex Distance (R.V.D.)
- Wrap (face form tilt)
- Near P.D.
- A, B, E.D. and D.B.L. values (frame measurements)
Depending on the lens design, we are able to take in account some or all of these measurements to optimize your lens design and resulting visual acuity and comfort.
Why are accurate measurements important?
High quality vision requires premium ophthalmic lenses and precise measurement of those lenses to ensure they are placed correctly in front of your eyes.
A measurement error as small as 1mm can drastically change the power of the lens as well as how well your eyes work together.
Image deflection (called “prism”), image distortion and visual fatigue are common symptoms of poorly positioned lenses or those ordered through on-line channels without proper measurement.
Your eyes are your window to the world – after investing in the time and cost of an eye exam, why compromise on the glasses you purchase? Trust an eye care professional (optometrist/optician) at Campus Vision to provide the best possible result with your prescription.