There are average segment heights for each frame, but it can be important to have an accurate segment height for your eyes with a particular frame. SEGMENT HEIGHT (Seg Ht) - The distance from the lowest portion of the lens to the top horizontal line of the Segment or change in power (Your pupil height from the bottom of the frame). READING PORTION (PROGRESSIVE, BIFOCAL, TRIFOCAL)ĪDD, ADD POWER, SEG POWER - For near vision or reading, it is the additional power in the lower portion of a multifocal lens (progressive, bifocal, or trifocal). Only these four positions exist, however, orientations between these four positions can be specified by using combinations of horizontal and vertical prisms in the same lens. Only a small percentage of eyeglass prescriptions include prism.īASE - Rotation of the prism that is simply specified as 'base in' (where 'in' means towards the nose)or 'base out' or 'base up' or 'base down'. PRISM -This is the amount of prismatic power, measured in prism diopters, prescribed to compensate for eye alignment issues. If an eyeglass prescription includes cylinder power, it also must include an axis value, which follows the cyl power and is preceded by an "x" when written freehand. It is not enough to specify how much astigmatism there is you have to know where the difference in curvature is taking place. It reveals the orientation of the astigmatism. There may not be a value of cylinder in your prescription.ĪXIS - This is a number anywhere between 0 and 180 degrees.
OD OS WHICH IS RIGHT AND LEFT PLUS
Again, there is always a plus (+) or minus (-) sign present. If the vision in one eye is very poor, the word 'balance' or 'bal' may be written.ĬYL - CYLINDER: This is the measure for astigmatism. There will always be a value for sphere, even if it is just zero (written as 0.00, Plano or PL). The lens power for the distance correction will be minus while the correction for near distance and reading will be plus power. It always has a plus (+) or a minus (-) sign in front or above it. This value specifies the optical power of a lens in diopters. SPH - SPHERE: The amount of long or short sightedness. OS - O culus sinister, Latin for left eye. Sometime prescriptions use RE (right eye), LE (left eye), BE (both eyes).
OD - O culus dexter, Latin for right eye. Some prescription forms use ADD in place of NV with a single box to indicate the additional refractive power to be added to the spherical of each eye. This may represent a single-vision lens prescription to improve near object view, or the reading portion of a bifocal lens. For bifocals, this usually the prescription for the top half of the lens. Usually part of the prescription designed to improve far vision. Saland, contact Saland Vision by calling 21 or visiting website.To help you understand your prescription, here is a list of common optical terms often found in most eyeglass prescriptionsĭV - D istance vision. To learn more about eyeglass prescriptions or to schedule an eye exam with Dr. This number is the amount of additional correction your eyes need to focus at close distance and will always be a positive number. If you are getting bifocals or progressive lenses, there will be a number listed for ADD. It is the distance from the center of one pupil of the eye to the center of the pupil of another eye and is measured in millimeters (mm). Sometimes your prescription may also contain PD, which indicates the pupillary distance. Your prescription may have values shown for Cylinder (CYL) and Axis (AXI). OS is an abbreviation for the Latin phrase Oculus Sinister, meaning left eye. There are many other abbreviations on your eyeglass prescription. If the value has a minus sign (-), you are nearsighted if the number has a plus sign (+) or is not preceded by a plus sign or a minus sign, you are farsighted. On your eyeglass prescription, the value under the column OD Sphere (or OD SPH) indicates the amount of lens power, measured in diopters (D), prescribed to correct your nearsightedness or farsightedness.
The term “sphere” means that the correction for nearsightedness or farsightedness is spherical, meaning equal in all meridians of the eye. OD is an abbreviation for Oculus Dexter which is the Latin term for right eye. OD sphere is a term used for an eyeglass prescription.
What Does OD Sphere Mean? Submitted by salandvision on Ma6:46 pm
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