rx

Rx      -Abbreviation of the Latin word for "recipe."

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Diopter

The strength of a lens is measured in diopters, abbreviated D.

The higher the number of diopters, the stronger the lens

Lenses come in positive (plus) and negative (minus) strengths. You can usually tell whether a lens is positive or negative by looking through it.  Positive lenses tend to enlarge things when you look through them;  negative lenses tend to diminish the size of things when you look  through them.

Usually:

  • the "spherical" component is the main correction
  • the "cylindrical" component is "fine tuning."

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Spherical (SPH)      -   Basic correction reading

Cylindrical (CYL)     -   Fine tuning , the agstimatism reading

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D.V.      -    This part of the prescription describes the corrections for Distant Vision.

N.V.     -   "Near vision."

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O.D.      -   O.D. is an abbreviation for "oculus dexter," Latin for "right eye."

O.S.       -   O.S. is an abbreviation for "oculus sinister," Latin for "left eye."

     (Some eyeglass prescriptions simply say "left" and "right" instead of "O.S." and "O.D.")

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Agstimatism    -   a common condition where the cornea is not perfectly spherical

               Reading of  over plus 1 or over -1 are considered  higher and custom ground lenses are                     suggested