A millimetre ruler (preferred) or a PD ruler (available at optical stores).
A mirror, or a friend/family member to help.
A pen and paper to record the measurement.
Step 2: Understanding Pupillary Distance
Pupillary Distance (PD) is the distance between the centres of your pupils. This measurement is crucial for correctly fitting your prescription glasses, ensuring that the lenses align with your eyes.
Step 3: You then have the option to either
Measuring PD with a Mirror
Stand in front of a mirror: Stand about 8 inches (20 cm) away from the mirror.
Hold the ruler: Place the ruler against the bridge of your nose.
Align the zero: Close your right eye and align the zero mark of the ruler with the centre of your left pupil.
Measure the distance: Open your right eye and close your left eye. Look straight ahead and note the millimetre mark that lines up with the centre of your right pupil.
Record the measurement: Write down this number as your PD.
Measuring PD with Help from a Friend
Sit comfortably: Sit down with your head straight and your eyes looking forward.
Position the ruler: Have your friend place the ruler against the bridge of your nose.
Align the zero: Your friend should close one eye and align the zero mark with the centre of your left pupil.
Measure the distance: Without moving the ruler, they should then close their other eye and note the millimetre mark that lines up with the centre of your right pupil.
Record the measurement: Write down this number as your PD.
Step 4: Double-Check Your Measurement
Repeat the process: It's a good idea to measure your PD a couple of times to ensure accuracy. If using the mirror method, take at least three measurements and average them.
Step 5: Understanding Your Results
Single PD: This is the total distance between your pupils, usually used for single vision lenses.
Tips for Accuracy
Stay relaxed: Avoid tensing your eyes or forehead.
Look straight ahead: Keep your eyes looking straight to get an accurate measurement.
Use good lighting: Make sure you are in a well-lit area to clearly see the ruler and your pupils.
