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The phoropter is the diagnostic instrument used by the ophthalmologist or optometrist to calculate the subjective grading of the patient's vision. 

This tool has all the necessary lenses in one box to be able to take the patient's prescription as quickly and comfortably as possible.

Discover in Área Oftalmológica Avanzada how the phoropter works, what its parts are and what it is for. 


What is the phoropter?

The phoropter is the instrument that allows the optometrist review grace the patient.

It has an appearance similar to that of glasses but much larger and, inside, it has lenses of different graduations that the optometrist or ophthalmologist alternates to determine which one the patient sees better with. Depending on the value we obtain, we will determine the exact graduation of that person.

Inside the phoropter, filters, colored lenses, polarized lenses and prism systems are incorporated that allow us to evaluate the refractive state of a person, in addition to allowing us to detect diseases such as squint o phoria.

Parts of the phoropter

There are different models of phoropters, although almost all have the same controls: 

  • Control of spherical lenses and plano-cylinder negative lenses.
  • Auxiliary lens control and aperture control which offers several options such as the opening of the viewfinder and contains an occluder. This knob also contains a lens retinoscopy, pinhole, red and green filter, Maddox rods and Jackson cross cylinder. 
  • Adjustment controls to adapt the phoropter to the patient, knobs for interpupillary distance control, level control knob, vertex distance control and pantoscopic tilt control. 

The parts of a phoropter are: 

  • leveling knob.
  • Interpupillary distance scale.
  • Interpupillary distance adjustment knob.
  • convergence lever.
  • Device for placing the scale in VP.
  • cross cylinder.
  • Rotary prism.
  • Cylinder shaft control knob.
  • Cylinder power control knob.
  • Spherical Power Quick Selection Wheel.
  • Auxiliary lens control.
  • Spherical power control.
  • Spherical lens power reading window.
  • Cylindrical power reading window.
  • Auxiliary lens housing.
  • Front support adjustment knob.

What is?

El phoropter is mainly used to determine the subjective graduation of a patient that you need to wear glasses to correct a refractive error such as myopia, farsightedness or astigmatism.

There is talk of subjective graduation because, during the visual examination, it is the patient who must indicate to the optometrist with which lens or filter he can see better, therefore, the values ​​that we extract depend subjectively on what the patient indicates.

In addition, the phoropter can be used to measure phoria and determine what is the natural position of the eyes when they are at rest. You can also measure the ampaccommodative latitude of the eye, vertical and horizontal heterophobia and spherical power.

After using the phoropter, the optometrist may use the test glasses to corroborate that the subjective prescription of the patient is really the correct one to order the definitive glasses to be graduated.

En Área Oftalmológica Avanzada we have the most advanced phoropters in the industry. If you have any symptoms of refractive defect or want to check your graduation, do not hesitate to contact our medical experts. We will be happy to help you!

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Find out now about what a phoropter is, how it works, what its parts are and what it is used for.
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Área Oftalmológica Avanzada
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