What we need for each lens type
- Single vision: your PD (one number, for example 62 mm, or one for each eye).
- Bifocal: PD and the segment height for your frame.
- Progressive: PD for each eye separately (for example R 31 / L 32 mm) and the fitting height for the frame you choose. Faces are rarely exactly the same on both sides, and the narrow reading corridor must sit right in front of each pupil.
Three ways to give us your PD
- Already know it: type it at checkout. Check your old prescription or your last optician bill; it is often written as "PD" or "IPD".
- Card photo: stand facing a window, hold any ATM, PAN or Aadhaar card flat against your forehead just above the eyebrows, look straight at the phone held about an arm's length away, and take a photo. Send it to us on WhatsApp. The card is a known size (85.6 mm), so our optometrist measures your PD from the photo.
- WhatsApp video call: our optometrist guides you for about 10 minutes and measures your PD for each eye. Best for progressive lenses outside Chennai.
In Chennai? We measure in person
Visit our store in Arumbakkam, or book a home eye test (₹100 for the whole family). For progressive lenses we measure PD and fitting height with your actual frame on your face. This is the most accurate way.
Fitting height for progressive lenses
Fitting height is how high your pupil sits in the frame. It depends on the frame and how it rests on your nose, so it is never on a prescription. If you already wear progressives you are happy with, send a front photo wearing them with the card on your forehead and we match that position. Otherwise we use the standard height for your chosen frame and pick a lens design that suits it. Choose a frame with a lens height of at least 30 mm for progressives.
What happens to your order
If PD is missing, we hold your order (it is not sent to the lab) and message you on WhatsApp. Once PD is confirmed, the lenses go into production.
Do
- Check your old prescription for PD
- Use a real card for scale
- Look straight at the camera
- Pick a 30 mm+ tall frame for progressives
Don't
- Guess your PD
- Use one PD for progressives
- Take the photo at an angle
- Wear tinted glasses in the photo
See Fusion progressive lenses →
Questions
What is a normal PD?
Most adults are between 54 and 74 mm. Children are smaller. Always measure your own rather than using an average.
Can I measure PD at home with a ruler?
You can for single vision lenses, with someone else holding the ruler. For progressive lenses please use the card photo or a video call with our optometrist, because we need each eye separately.
My prescription is from another clinic. Can I still order?
Yes. Upload the prescription at checkout or choose "send power later". If PD is missing, we will help you measure it before making the lenses.
General information from the optometrists at LenzKare Optical & Eye Clinic, Arumbakkam, Chennai. It does not replace an eye examination. For sudden changes in vision, see an eye doctor the same day.