What is an Ophthalmic Refractometer?

Have you ever been to your eye care professional’s office and felt like they are speaking a completely different language? One of the phrases you may have heard at your last visit is ‘ophthalmic refractometer.’

A refractometer is a device used to measure the lens strength and power you need to correct refractive errors.


Basically, the refractometer will help your doctor identify refractive errors in the cornea of your eyes. Refractive errors prevent the light entering the eyes to focus properly on your retina, negatively impacting your vision.  The most common conditions causing refractive error are myopia (near-sightedness), presbyopia (far-sightedness), and astigmatism (an irregularly shaped cornea). The measurements provided by the refractometer help your eye care professional write a prescription for eyeglasses or contact lenses to correct your vision.

Here are some of the measurements needed to order glasses:

  • Myopia and presbyopia errors — If you are near-sighted or far-sighted, the refractometer lets the person making your lenses know just how strong you need the lenses to be to correct your vision. Sometimes, you may experience near-sightedness in one eye and far-sightedness in the other, or varying degrees of each condition between your two eyes.
  • Astigmatism levels and location — When you have an astigmatism, your eye is shaped sort of like a football, whereas people without astigmatism have perfectly round eyes. The refractometer will also show the needed lens power for your glasses, which combines information about your near- or far-sightedness with the severity of astigmatism you’re experiencing. Your lens producer will also need to know where your astigmatism is located.
  • Pupillary Distance (PD) — Your PD refers to the distance between the center of each of your pupils. We all have a unique facial and eye shape, so the PD is necessary for lens producers to ensure your glasses properly address your specific eye needs. This measurement is actually not taken with a refractometer because it’s not a clinical measurement and is usually taken during your eyeglasses fitting.
    • You can however measure your own pupillary distance at home with a PD ruler. Learn how here.

Did you know you can find the measurements you need to order your eyeglasses listed above with EyeQue? The EyeQue Personal Vision Tracker (PVT) is an ophthalmic refractometer you can use at home. Click here to learn more.


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7 Reasons Why You Should Test Your Vision from Home

5 Things You Should Know About the Accuracy of the Personal Vision Tracker (PVT)