Eye Prescription Calculator: Understand Your Vision

Do you find yourself squinting at street signs or struggling to read your favorite book? Understanding your eye prescription is the first step toward clear vision. While only an eye care professional can provide a comprehensive eye exam and accurate prescription, knowing how to interpret the numbers can empower you to better understand your vision needs. — Arizona Diamondbacks: Game Schedules & Info

Let's break down the components of an eye prescription and how to make sense of them. — Krest Ridge Funeral Home: Services & Information

Decoding Your Eye Prescription

An eye prescription contains a series of abbreviations and numbers, each representing a specific aspect of your vision. Here's a breakdown of the key terms: — Find United Healthcare In-Network Providers

• OD (Oculus Dexter): This refers to your right eye.
• OS (Oculus Sinister): This refers to your left eye.
• OU (Oculus Uterque): This refers to both eyes.
• Sphere (SPH): This number indicates the amount of lens power, measured in diopters (D), needed to correct nearsightedness (myopia) or farsightedness (hyperopia).
  • A minus sign (-) indicates nearsightedness. The higher the number, the stronger the prescription needed to correct distance vision.
  • A plus sign (+) indicates farsightedness. The higher the number, the stronger the prescription needed to correct close-up vision.
• Cylinder (CYL): This number indicates the amount of lens power needed to correct astigmatism, which is an irregular curvature of the cornea or lens. It is also measured in diopters (D).
  • Like the sphere, the cylinder can be a minus or plus number. The further away from zero, the more correction you need.
• Axis: This number indicates the orientation of the astigmatism, measured in degrees (1 to 180). It specifies the angle at which the cylinder power should be applied.
• Add: This number indicates the added magnifying power needed to correct presbyopia, a common age-related vision condition that makes it difficult to focus on close-up objects. This is typically found on prescriptions for bifocals or progressive lenses. It is always a positive number, even if not explicitly written with a plus sign.
• Prism: This indicates the amount of prismatic power needed to correct eye alignment problems that cause double vision or eye strain. It's measured in prism diopters (PD).
• Base: This refers to the direction of the prism. It can be either:
  • BU (Base Up)
  • BD (Base Down)
  • BI (Base In)
  • BO (Base Out)

Example Prescription

Let's look at an example to illustrate how to interpret an eye prescription:

In this example:

• The right eye (OD) requires -2.00 diopters of correction for nearsightedness and -0.75 diopters of correction for astigmatism at an axis of 180 degrees. An additional +2.25 diopters of power are required for near vision tasks.
• The left eye (OS) requires -1.50 diopters of correction for nearsightedness and -0.50 diopters of correction for astigmatism at an axis of 090 degrees. An additional +2.25 diopters of power are required for near vision tasks.

Important Considerations

• Always consult with an eye care professional: This information is intended for educational purposes only and should not be used to self-diagnose or treat any vision problems. Regular eye exams are essential for maintaining good eye health and ensuring accurate prescriptions.
• Prescriptions can change: Your vision can change over time, so it's crucial to have your eyes examined regularly to update your prescription as needed.
• Contact lenses vs. eyeglasses: Contact lens prescriptions differ from eyeglass prescriptions. A contact lens fitting and evaluation are necessary to determine the appropriate contact lens parameters.

Understanding your eye prescription empowers you to actively participate in your eye care. By knowing what the numbers mean, you can better communicate with your eye doctor and make informed decisions about your vision correction options. Schedule regular eye exams and prioritize your eye health for a lifetime of clear vision. Find an eye care professional near you.