TRANSPOSING PRESCRIPTIONS

In the sample Rx on the previous page, numbers 13 through 17 deal with second-pair recommendations. In the example shown, the doctor has indicated that the patient needs prescription sunwear to be worn as needed.

The doctor could have also indicated that the patient needs reading-only glasses or intermediate glasses. In either of those cases, the Rx would likely have been transposed by the doctor and included in section 15 of the sample prescription. However, the doctor could have left it to the dispenser to transpose the Rx for these range-specific glasses. As a result, all dispensers should know how to transpose prescriptions when necessary.

TECH TALK

Here’s more important information about prescriptions, including additional details about some of the key terms used when writing, reading, discussing, or releasing a patient’s prescription.

ADD POWER

The add power (for presbyopic patients) typically ranges from +0.75 to +3.00D. Early presbyopes need a lower degree of magnification to help them read (such as a +0.75), whereas more advanced presbyopes require a stronger degree of plus power for reading such as a +2.50 to +3.00D.

CONTACT LENSES

An eyeglass prescription isn’t the same as a contact lens prescription. Our example Rx does not include contact lens information. The parameters, powers, and fitting information for contacts is different than that of glasses because contacts are fitted on the surface of the eye. A contact lens prescription includes the manufacturer and brand of contacts, the diameter of the lenses, the base curve, and the lens power.

CYLINDER

With astigmatism, an irregular-shaped cornea or lens prevents light from coming to a sharp focus on the retina, resulting in blurred vision at all distances. The number in the cylinder column (#7 on previous page) will have either a minus sign or a plus sign in front of it. Optometrists tend to refract in minus cylinder, so a prescription from an O.D. will generally have a minus sign (-) in front of the cylinder power. Ophthalmologists typically refract in plus cylinder, so an Rx from an ophthalmologist will usually have a plus sign (+) in front of the cylinder power.

OD, OS, OU

These abbreviations are Latin terms traditionally used in eyewear prescriptions. “OD” stands for oculus dexter which is the right eye; “OS” is the abbreviation for oculus sinister which is the left eye. “OU” is the abbreviation for oculus uterque which denotes both eyes.

PLUS and MINUS

Myopia means nearsighted and this correction always includes a minus (-) sign before the sphere power. Hyperopia refers to farsighted patients. These prescriptions include a plus (+) sign before the sphere power.

PRESCRIPTION RELEASE RULE

The Federal Trade Commission’s Prescription Release Rule, proclaimed in 1978, requires that optometrists and ophthalmologists provide their patients with a copy of their eyeglass prescription immediately after an eye exam is completed and at no extra cost. By having a written copy of the prescription, patients have the option of purchasing eyewear from a provider of their choice.

PRISM

Prism refers to the amount of prismatic power included in the Rx, if any, and is given in prism diopters. There is usually a small triangle drawn near the prism power to indicate that the Rx includes prism correction.

Having a better understanding of the abbreviations, terms, and numbers on an eyeglass prescription will help dispensers provide patients with eyewear that improves their visual acuity.