If you need glasses, your eye doctor will provide you with a prescription for corrective lenses. Eyeglass prescriptions may be written in different ways, though most are either printed or handwritten in horizontal rows.

The first row is the prescription for the right eye (OD), and the second row is for the left eye (OS). Within each of these rows are three values: Sphere (SPH), Cylinder (CYL), and Axis. The SPH number corrects for nearsighted [indicated with a minus (-)] or farsighted [indicated with a plus (+)] vision. The CYL number and AXIS number correct for astigmatism. You may also have another field labeled as ADD which corrects for the reading power used in a bifocal or progressive lens.

Lastly, eyeglass prescriptions sometimes include the pupillary distance (PD) measurement, which is the distance between your pupils. PD is needed to determine where the optical center of the lens will be for clear, accurate vision.

Your pupillary distance (PD) is the measurement of the distance between your pupils. If you already wear eyeglasses from our brand, we may have your PD on record. If not, you can request it from your latest prescription provided by us.

If you need to measure your own PD, it's simple. Stand in front of a mirror with a ruler. Close one eye and align the ruler's zero mark with the center of your open eye's pupil. Look straight ahead while keeping the ruler steady and have someone help measure the distance from the center of that pupil to the center of the other pupil in millimeters. Repeat a couple of times for accuracy.

Alternatively, you can download our PD ruler to measure your PD yourself. Just print it out, follow the instructions, and ensure you have an accurate measurement before ordering your eyeglasses.

You bet we can!

Single-vision Rx:
Up to -20.00 or +12.00 on the Sphere (SPH
Up to + or - 6.00 on the Cylinder (CYL).

Bifocal Rx:
Up to -9.00 or +6.00 on the SPH.
Up to + or - 6.00 on the CYL.
Up to +3.50 on the NV-ADD.

Progressive Rx:
Up to -10.00 or +8.00 on the SPH.
Up to + or - 6.00 on the CYL.
Up to +3.50 on the NV-ADD.

Ordering reading glasses through Syght is easy! Once you have selected a frame, click “Order Glasses” and follow the below steps:

1. First, indicate that you would like reading glasses by selecting “Single vision” from the Prescription Type drop-down.

2. Next, you’ll need to input a Near Single or Dual PD (pupillary distance) under the Pupillary Distance dropdown. For a Single PD, if you were only given one PD measurement, it is most likely for distance so you will need to subtract 3 to calculate your near single PD. If you were given a dual PD, two numbers - one for the right and left eye, you’ll need to subtract 1.5mm from each number to calculate the near dual PD. Ex. If given PD= 63mm then Near PD= 60mm.

3. The last step is to enter the reading prescription for the right eye and left eye. If your doctor didn’t write out a separate reading prescription then you’ll need to calculate it yourself. You can do this by adding the ADD value to the SPH value and keeping the remaining values the same, as in the example below:

Most people have an astigmatism. If you have an astigmatism on your Rx, we can make glasses that will correct it.