Pupillary Distance (PD) is the distance, in millimeters, between the center of one pupil to the center of the other. The PD is needed to manufacture your eyeglasses because it determines the exact optical center of the lens, which is the point where you look through the lens. PD is especially important for manufacturing progressive lenses.

 

Once you have your PD, you can upload your photo to the Frame Fit tool and begin trying on glasses. The Frame Fit tool allows you to see exactly what the glasses look like on you and how well they fit the size and shape of your face. If you don’t have your PD, you can find out how to measure it here.

Pupillary Distance (PD) is the distance, in millimeters, between the center of one pupil to the center of the other. The PD is needed to manufacture your eyeglasses because it determines the exact optical center of the lens, which is the point where you look through the lens. PD is especially important for manufacturing progressive lenses.

 

Once you have your PD, you can upload your photo to the Frame Fit tool and begin trying on glasses. The Frame Fit tool allows you to see exactly what the glasses look like on you and how well they fit the size and shape of your face. If you don’t have your PD, you can find out how to measure it here.

Bifocal

 

A lens with two fields of vision separated by a line. Generally the top is designated for distance-vision or computer-distance and the bottom for near-vision work such as reading.

 

In a Bifocal lens, the two fields of vision are specifically differentiated by a visible line. The bottom reading area is 28mm wide and is positioned just below the centerline of the lens. The physical position of the bi-focal area will be affected by the physical height of the lens chosen.

 

The total lens height for a Bifocal lens must be 30mm or greater. We recommend a taller lens for more comfortable wear, but 30 mm is the minimum height for a bifocal lens. If the frame chosen has a lens height smaller than 30mm, a different frame must be chosen for Bifocal lenses.

 

 

Progressive

 

This refers to the lens design which includes three fields of vision, without lines, and is sometimes referred to as a "no-line multi-focal".

 

In a progressive lens, the shape of the corrected part of the lens is approximately that of a funnel or a mushroom.  The top portion is for distance-vision, narrowing to the lower middle for mid-range, finally to the bottom portion for the near-vision or reading. The reading area is expected to be smaller than the distance area.  People sometimes prefer a single-vision lens for extended reading or up-close work.

 

The lens height for a progressive lens must be 30mm or greater. We recommend a taller lens for more comfortable wear, but the minimum lens height is 30 mm. If this frame has a lens height smaller than 30mm, a different frame must be chosen for progressive lenses.