What Is the Difference Between a Phoropter and Autorefractor?

The difference between a phoropter and an autorefractor lies in their functionality and the way they measure and determine your prescription. Both devices are utilized in the field of optometry to assess the focusing ability of your eyes and assist in determining the appropriate corrective prescription. However, while a phoropter requires your active participation in looking at a letter chart and providing feedback on the clarity of your vision during the examination process, an autorefractor offers a more automated approach. By employing advanced technology, an autorefractor is able to make automatic adjustments without the need for subjective input from the patient, eliminating the necessity of interacting with a letter chart. This makes the autorefractor a more convenient and efficient option for measuring and determining your prescription, as it provides a fast and objective assessment of your visual acuity.

Is Autorefractor Subjective or Objective?

An autorefractor is generally considered to be an objective device rather than a subjective one. Unlike the traditional method of subjective refraction, which relies on the patients interpretation and feedback, an autorefractor uses advanced technology to measure the eyes refractive error precisely. This technology involves a combination of wavefront analysis, optical principles, and computer algorithms to calculate an accurate prescription.

This measurement provides information about the eyes focusing power and any potential refractive errors, such as nearsightedness, farsightedness, or astigmatism. The process is quick, typically taking only a few seconds, and produces highly accurate results.

This makes it particularly useful in situations where patients may have difficulty expressing their visual needs or children who may not be able to provide reliable feedback. Additionally, the objective nature of the autorefractor reduces the chances of human error or bias, resulting in more consistent and reliable outcomes.

Other tests, such as visual acuity assessments and a thorough evaluation of the eyes health, are also essential in determining the most accurate and appropriate prescription for glasses or contact lenses.

It’s efficiency, accuracy, and ability to remove human error make it a valuable tool in helping eye care professionals deliver the best possible care to their patients.

The difference between a refractor and a phoropter lies in the name. While some may use the term “phoropter” to refer to any refracting instrument, the original and trademarked name is the Phoroptor from Reichert Technologies. Reichert Technologies is a globally recognized leader in the design and manufacturing of diagnostic devices for eye care professionals. The correct spelling of both “refractor” and “Phoroptor” is with an “or”.

What Is the Difference Between a Refractor and a Phoropter?

A refractor and a phoropter are both instruments used in optometry to determine a patients refractive error and prescribe corrective lenses. However, there are some key differences between the two.

A refractor is a manual instrument that consists of a series of lenses and prisms. It’s used by an optometrist or ophthalmologist to measure the patients refractive error by presenting different lens options and asking the patient which one provides the clearest vision. The refractor is manually adjusted by the practitioner to change the lenses and measure the patients visual acuity.

However, the phoropter allows for quicker and more precise adjustments of lenses, making the examination process more efficient.

The phoropter is usually mounted on an adjustable stand and positioned in front of the patients eyes. The patient looks through the instrument and the practitioner can control the lenses and prisms using knobs or buttons.

However, it’s worth noting that the term “phoropter” is often used interchangeably with “refractor” in colloquial language, even though they technically refer to different instruments.

The Role of Refractors and Phoropters in Diagnosing Other Eye Conditions Besides Refractive Errors

Below is a list of the role of refractors and phoropters in diagnosing other eye conditions besides refractive errors:

  • Evaluating the presence of astigmatism
  • Measuring the extent of presbyopia
  • Determining the presence of strabismus
  • Assessing binocular vision disorders
  • Diagnosing accommodative disorders
  • Identifying the need for prism correction
  • Evaluating ocular muscle imbalance
  • Assessing convergence and divergence insufficiency
  • Determining the existence of amblyopia (lazy eye)
  • Diagnosing certain types of cataracts
  • Assessing the presence of corneal irregularities
  • Evaluating the need for vision therapy
  • Monitoring the progression of certain eye conditions

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The term “phoropter” is widely recognized in the field of optometry as a vital instrument for assessing visual acuity and determining a patient’s eyeglass prescription. However, few are aware of the intriguing trademark origin behind this name. The term was specifically coined for the latest iteration of the phoro-optometer developed by DeZeng Standard of New Jersey, and it was officially registered as a trademark with the USPTO on April 25, 192Let’s delve further into the history and significance of this renowned ophthalmic device.

Why Is It Called a Phoropter?

The phoropter, a vital tool in optometry, gained it’s name from a combination of two terms: “phoro” and “optometer.”. The term “optometer” refers to an instrument used to measure various aspects of vision, such as refractive errors. On the other hand, “phoro” originates from the Greek word “phoros,” meaning “to bear” or “to carry.”. This connotes the purpose of the instrument, which is to carry or bear the ability to measure the refractive errors in a patients vision.

The origins of the term “Phoroptor” can be traced back to April 25, 1921, when DeZeng Standard of New Jersey filed for a trademark with the United States Patent and Trademark Office (USPTO). The trademark registration under serial number 71146698 was completed, and ownership of the trademark currently resides with Reichert Technologies.

The Phoroptor has undoubtedly revolutionized the field of optometry, enabling practitioners to accurately assess and diagnose refractive errors such as nearsightedness, farsightedness, and astigmatism. By utilizing different lenses and settings, the Phoroptor allows optometrists to determine the most appropriate prescription for each individual patient, thereby maximizing their vision correction.

How the Phoropter Is Used in an Eye Exam

The phoropter is a tool used by optometrists during an eye exam to determine the patient’s prescription for corrective lenses. It consists of a series of lenses that can be adjusted to find the combination that provides the clearest vision. The optometrist will ask the patient to look through the phoropter while reading a chart and will systematically switch the lenses until the patient reports the sharpest vision. This process helps the optometrist accurately assess the patient’s vision and prescribe the appropriate lenses for correction.


While both devices are used to measure the ability of the eyes to focus and determine the prescription for corrective lenses, a phoropter requires the patient to actively view a letter chart and provide feedback on the clarity of their vision. This automated process simplifies and expedites the examination, potentially making it a more efficient and convenient option for both the patient and the eye care practitioner.