Interpreting the Numbers

Optometrists determine the need for vision correction during an eye exam. Therefore, astigmatism, farsightedness, and nearsightedness receive a number that identifies the extent of the condition. Each eye gets a set of numbers because both eyes rarely need the same correction. The design and production of your glasses depend on the numbers your optometrist puts in your prescription. Incomplete for contact lenses, the measurements in an eye exam need additional information for contacts. Because they sit directly on the eye, contacts require a particular exam and a separate set of values.

Sphere
The plus or minus sign before the first number indicates the type of correction, while the number reveals the amount of lens power you need. For example, a minus sign means the correction applies to nearsightedness. Similarly, a plus sign refers to farsightedness correction.

Cylinder
About a third of Americans have astigmatism, which causes eye strain, headaches, fatigue, and distorted or blurred vision. Cylinder defines values that relate to the lens power you need to correct astigmatism. The number measures how much astigmatism you have in your vision. Similar to the eye exam findings for Sphere, a minus sign refers to nearsighted astigmatism. The plus sign means the correction applies to farsightedness. The larger the number, the greater your astigmatism and need for corrected vision. When an optometrist enters no value, you have no astigmatism.

Using Supportive Measures for Specific Purposes

A typical prescription presents values for Sphere, Cylinder, and Axis to reflect the need for vision correction for any patient who receives an eye exam. However, some prescriptions may include supportive evidence that further defines conditions.

Axis
Related only to astigmatism, Axis tells your optometrist the angle degrees for where the condition occurs in each eye. Unless your prescription shows a value for lens power in the Cylinder measures, it does not include a measure for Axis.

Add
An instruction for progressive or bifocal lenses appears in the Add column. The value indicates the additional magnifying power that the lower part of a multifocal lens may need. Neither a plus nor a minus sign appears with the values for Add. However, measures for Add always have positive value. Most patients need the same value for both eyes.

Prism
Patients who have double vision may receive a prescription that has a value that compensates for issues with image alignment. For example, a value appears in the Prism column when the eyes do not focus properly.

Noting Differences Between Prescriptions for Glasses and Contacts

In an exam for patients who prefer contact lenses, some additional measures address issues that eyeglass wearers do not need.

Base Curve
A contact lens must fit snugly and flawlessly across the eye’s surface. A Base Curve measures how much curvature occurs in the eye’s shape.

Diameter
The differences in the size of eyeballs may not amount to more than 6 millimeters, but it can seem enormous when contacts must fit the shape precisely. A measure of the diameter prevents using a lens too small or too large to fit correctly.

Type of Material
At Beyond 2020 Vision Specialists in Odessa, patients can choose the latest and most advanced materials for contacts. Options include lenses for monovision, multifocal, regular, and high astigmatism lenses. In addition, patients may benefit from modified monovision and single-vision contact lenses.

Choosing the Finest in Eyecare and Eyewear

The high-end lenses from Essilor give patients at Beyond 2020 Vision Specialists the best access to corrected vision. As a result, patients receive the clarity of vision that resolves issues. Most concerns relate to glare, digital eye strain, astigmatism, nearsightedness, and farsightedness.

Residents of Odessa and neighboring communities of Cheval and Trinity have access to expert care by Dr. Christopher Tumolo at Beyond 2020 Vision Specialists. A return to bygone days when doctors took time to understand patients without hurry or haste distinguishes his practice. A convenient location at 16230 State Road 54 in Suncoast Crossings shopping center next to the Suncoast Parkway requires only a short drive. A prescription that corrects glare, astigmatism, nearsightedness, or farsightedness gives clients peace of mind. In addition, it provides reassurance about taking proper care of vision issues. Residents or visitors to the area may schedule an eye exam by calling 813-926-5993 for an appointment.