The prescription is the key information for making prescription glasses, but there is an important measurement that is essential for progressive glasses. The lens centers are necessary in this type of glasses so that the user has comfortable and optimal vision.
What are the lens centers?
It refers to the exact point where our pupil is located behind the lens. In other words, the exact point where our eyes are looking straight ahead. Depending on the frame design and lens size, the centers vary.
Why are the centers important in progressive glasses?
Progressive glasses are those that correct vision problems for both distance and near in the same lens. The midpoint of the lens where the prescription changes from distance to near is essential for the user's correct vision.
How can I measure the centers of my frame myself?
If you have a frame and want to change only the lenses to progressive ones, taking the centers is easy. There are two methods:
- With the glasses frame on, look straight ahead in a mirror and mark exactly the point where your pupil falls with a marker.
- For more accuracy, ask someone to mark with a marker the points on the lens (or the template that comes with the glasses) that fall exactly where your pupil is.
The precise measurements used to determine the lens center are the pupillary distance, PD (from the pupil to the center of the nose), and the height, H (from the pupil to the lower edge of the glasses). Many prescriptions provided by the optician and ophthalmologist include these measurements.
If you already have progressive glasses and want to renew the complete frame or just the lenses, the lenses from the previous glasses are enough for the optical shop to take the center measurements.
What if I also buy the frame from you and don’t have the center measurements?
We will take the necessary steps to make your glasses perfect. We will deliver the frame to you first so you can mark the centers, then we will collect the frame and bring it back to our optical shop to fit the progressive lenses.
Do you have any questions? Contact us and we will help you. With this explanatory video, it will be much easier for you to take your centers at home.
