Lense

PRESCRIPTION
DISTANCE
For distance vision correction, because people can not see things far.
NEAR VISION
For Near vision correction, because people can not see things very close.
BIFOCALS
For distance and near vision corrections, so people can read the book while watch TV at same time.
PROGRESSIVES
No-Line Bifocal. For distance and near vision corrections, so people can read the book while watch TV at same time.

PESCRIPTION (RX)

SPHERICAL (SPH)
The value for SPH indicated the power of the lens measured in diopters (D) required for correcting vision. The minus sign (-) indicates the use of a concave lens to correct nearsightedness. The plus sign (+) indicates the use of a convex lens to correct farsightedness. The lens refracts light to the retina to allow the greatest visual acuity.

CYLINDER (CYL)
Cylinder (CYL). This indicates the amount of lens power for astigmatism. If nothing appears in this column, either you have no astigmatism, or your astigmatism is so slight that it is not really necessary to correct it with your eyeglass lenses.
The term "cylinder" means that this lens power added to correct astigmatism is not spherical, but instead is shaped so one meridian has no added curvature, and the meridian perpendicular to this "no added power" meridian contains the maximum power and lens curvature to correct astigmatism.
The number in the cylinder column may be preceded with a minus sign (for the correction of nearsighted astigmatism) or a plus sign (for farsighted astigmatism). Cylinder power always follows sphere power in an eyeglass prescription.
Meridians of the eye are determined by superimposing a protractor scale on the eye's front surface. The 90-degree meridian is the vertical meridian of the eye, and the 180-degree meridian is the horizontal meridian.

AXIX
Axis refers to the angle of the correction for the astigmatism in the eye(if one exists) from 1 to 180.
If there is an OD Axis value, there must be an OD CYL (Cylinder) value.
If there is no OD Cylinder value, or if the OD Cylinder value is Zero, then the OD Axis value is Zero.
The Axis value is usually written in 3 digits, which means if your Axis value is 5,it is often written as 005. This Axis value is still 5, regardless of how it is displayed.

ADD
Is an abbreviation for "near vision". This may represent a single-vision lens prescription to improve near work. or the reading portion of a bifocal lens. Some prescription forms use ADD in place of "N.V" with a single box to indicate the additional refractive power to be added to the spherical of each eye.

PUPILLARY DISTANCE (PD)
The PD or Pupillary Distance is the distance between the pupils of the eyes, center to center, in millimeters.

Most people have a PD between 54mm and 74mm.Select your PD value from the drop down to show only frames that will work for you.Your optometrist should have given you your PD value as part of your prescription. If you received two values (such as 31/32), they will be the distances from the center of the nose to each eye. Add them together to get the single PD value (31+32=63).
Sometimes you may receive two PD numbers that are off by a value of 3mm (such as 62/59). The larger value is the distance PD, which is what you will normally need for our site. The smaller value is used only for ordering reading glasses.If your most recent eye exam did not include the PD value, but a previous one did, you can use the previous value.
This does not change over time (except for children, of course).While an optometrist's PD value is always recommended, you can get this measurement yourself. Have a friend or family member measure it by holding a ruler just below your eyes and measure the distance in mm from center to center.
Make sure you are not looking at the person, but focusing straight ahead off in the distance, and keep your eyes steady. Take a few measurements for consistency.Do not ever try to guess your PD value, or try to measure anything on your current glasses, since there is no way to measure your PD from them.

PRISM
Prism is a feature that is added to a lens prescription to help the eyes work together and stay in proper alignment.


VERTICAL PRISM
Vertical Prism is used to help correct vertical eye misalignments and is prescribed in opposite directions for both eyes.

HORIZONTAL PRISM
Horizontal Prism is used to help correct lateral eye misalignments and is always prescribed in the same direction for both eyes.