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Is an optometrist or an automated machine more accurate in determining your eyeglass prescription?

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  • walfor


    Refractive error determination presupposes that all externalities are controlled or accounted for and that the measurement can be akin to a physical measurement. It is true that an autorefractor can produce a refractive error reading faster than a human, but the variability of even 10 or even 20 readings is sufficient that an average is usually taken to come up with a single number. On the other hand, through experience or skill, an optometrist determines refractive error by using a paradigm of interval testing that gradually narrows down the reading that becomes the refractive error. In the former, it is a physical measurement but one that requires averaging in a defined way. In the latter it is a psychophysical measurement where the optometrist and the patient "agrees" that a certain end point should represent the refractive error. The optometrist averages these readings in their head and within a moment. In summary, the accuracy question is related to the context of the test and whether human interaction is permitted. Both are good readings, but one is more likely to be more tolerable to wear as glasses than the other.
  • Michael anderson


    Determining refractive error is only one part of the prescribing process and needs to be considered along with other exam findings to get a final prescription. Automated machines can get a good idea of refractive error, but can't "think" to achieve the optimal final power to be prescribed. Although biased, my correct vote is for the optometrist ;) Most eye doctors use automated instruments as part of the process, though.
  • Alexia gerard


    Your eye doctor also may use an autorefractor or aberrometer to automatically determine your prescription. With both devices, a chin rest stabilizes your head while you typically look at a pinpoint of light or other image. An autorefractor, like a manual refraction, determines the lens power required to accurately focus light on your retina. Autorefractors are especially useful in certain cases such as evaluating young children who may not sit still, pay attention or interact with the eye doctor adequately for an accurate manual refraction.Studies have shown that modern autorefractors are very accurate. They also save time. The autorefraction takes only a few seconds, and the results obtained from the automated test greatly reduce the time required for your eye doctor to perform a manual refraction and determine your eyeglass prescription. An aberrometer uses advanced wavefront technology to detect even obscure vision errors based on the way light travels through your eye. Aberrometers primarily are used for custom or wavefront LASIK vision correction procedures, but many eye doctors are now incorporating this advanced technology into their routine eye exams as well.