What does power mean when ordering contact lenses?
When it comes to ordering contact lenses, understanding the concept of “power” is crucial. Power, also known as the diopter, refers to the strength of the lens required to correct vision issues such as nearsightedness, farsightedness, and astigmatism. In this article, we will delve into the meaning of power in contact lenses and how it affects your vision correction experience.
Understanding the Power Scale
The power of a contact lens is measured in diopters (D), and it is an essential factor to consider when ordering lenses. The diopter scale ranges from -20.00D to +20.00D, with most people falling within the -3.00D to +3.00D range. Here’s a breakdown of the power scale:
– Nearsightedness (Myopia): If you are nearsighted, you will have a negative power value. The lower the number, the less severe your nearsightedness. For example, -1.00D indicates a mild case of myopia, while -5.00D indicates a more significant degree.
– Farsightedness (Hyperopia): If you are farsighted, you will have a positive power value. The higher the number, the more severe your farsightedness. For example, +1.00D indicates a mild case of hyperopia, while +5.00D indicates a more significant degree.
– Astigmatism: Astigmatism is a condition where the cornea is irregularly shaped, causing blurred vision. It is often accompanied by nearsightedness or farsightedness. Astigmatism is corrected with a combination of spherical and cylindrical powers. The spherical power corrects nearsightedness or farsightedness, while the cylindrical power corrects astigmatism.
Choosing the Right Power
To choose the right power for your contact lenses, it is essential to consult an eye care professional. They will conduct a comprehensive eye examination to determine your prescription, including the appropriate power for your lenses. This process typically involves the following steps:
1. Refraction test: The eye care professional will use a phoropter to measure the power of your lenses. You will be asked to look through various lenses and indicate which one provides the clearest vision.
2. Pupillary distance (PD) measurement: The distance between your pupils is essential for proper lens fitting. Your eye care professional will measure this distance to ensure your lenses are centered correctly on your eyes.
3. Trial fitting: Before ordering your contact lenses, you may undergo a trial fitting to ensure the lenses are comfortable and provide clear vision. During this process, your eye care professional will assess the fit, comfort, and vision quality of the lenses.
Final Thoughts
In conclusion, the power of contact lenses is a critical factor to consider when ordering lenses. It determines the strength of the lens required to correct your vision issues. To ensure you receive the correct power, it is essential to consult an eye care professional for a comprehensive eye examination. By understanding the power scale and the factors that influence it, you can make an informed decision when ordering contact lenses and achieve optimal vision correction.
