Your PD should be exact. If your lenses aren't centered correctly, they can cause discomfort and eye strain. A small margin of error might not cause problems, but it's better to be as accurate as possible.2020-05-13
What if my PD is off by 2mm?
If the PD measured was 2mm off initially, by using a millimeter rule, the net cumulative error might be 4.5mm or more.
How much can your PD be off?
During the day, your PD can vary about 3-4 mm depending on your viewing distance. For instance, if your PD is 61 mm when looking at distant objects (i.e. street signs, chalkboard, TV, etc.), it narrows to 57-58 mm when viewing objects within 16-24 inches from your eyes.2018-10-23
How do you read PD on a prescription?
- BO (base out)
- BU (base up)
- BI (base in)
- BD (Base-down)
Does PD have to be exact?
Your PD should be exact. If your lenses aren't centered correctly, they can cause discomfort and eye strain. A small margin of error might not cause problems, but it's better to be as accurate as possible.2020-05-13
What if I measure my PD wrong?
When you get glasses made, the pupil distance measurement is taken to ensure that the lens center is in line with your pupil center. ... The wrong PD can induce eye strain, fatigue, headaches and blurry vision.2017-12-26
How do I find my PD for glasses?
MEASURING YOUR OWN PD Close your right eye and align the ruler's zero to the center of your left pupil. While looking straight, close your left eye and open your right eye. Read the mm line that lines up with the center of your right pupil. This number is your PD.