Editing Refractive error (section)

==Diagnosis==
[[File:Refrarction error test.JPG|upright=1.3|thumb|A doctor uses a trial frame and trial lenses to measure the person's refractive error.]]
Blurry vision may result from any number of conditions not necessarily related to refractive errors. The diagnosis of a refractive error is usually confirmed by an [[eye care professional]] during an [[eye examination]] using a large number of lenses of different optical powers, and often a [[retinoscope]] (a procedure entitled ''[[retinoscopy]]'') to measure objectively in which the person views a distant spot while the clinician changes the lenses held before the person's eye and watches the pattern of reflection of a small light shone on the eye.  Following that "objective refraction" the clinician typically shows the person lenses of progressively higher or weaker powers in a process known as ''[[subjective refraction]]''.
[[Cycloplegic]] agents are frequently used to more accurately determine the amount of refractive error, particularly in children<ref name=":0" />

An [[automated refractor]] is an instrument that is sometimes used in place of retinoscopy to objectively estimate a person's refractive error.<ref>{{cite web|title = Frequently Asked Questions: How do you measure refractive errors?|work = The New York Eye And Ear Infirmary|url = http://www.nyee.edu/faqlist.html?tablename=faq&key=36|access-date = 2006-09-13|url-status = live|archive-url = https://web.archive.org/web/20060901064328/http://www.nyee.edu/faqlist.html?tablename=faq&key=36|archive-date = 2006-09-01}}</ref> [[Shack–Hartmann wavefront sensor]] and its inverse<ref>{{cite web|title = NETRA: Inverse Shack-Hartmann Wavefront Sensor using High Resolution Mobile Phone Display|work = Vitor F. Pamplona, Ankit Mohan, Manuel M. Oliveira, Ramesh Raskar|url = http://web.media.mit.edu/~pamplona/NETRA/|access-date = 2011-12-13|url-status = dead|archive-url = https://web.archive.org/web/20111221185852/http://web.media.mit.edu/~pamplona/NETRA/|archive-date = 2011-12-21}}</ref> can also be used to characterize [[Aberrations of the eye|eye aberrations]] in a higher level of resolution and accuracy.

Vision defects caused by refractive error can be distinguished from other problems using a [[pinhole occluder]], which will improve vision only in the case of refractive error.<ref>{{Cite journal |last1=Schiefer |first1=Ulrich |last2=Kraus |first2=Christina |last3=Baumbach |first3=Peter |last4=Ungewiß |first4=Judith |last5=Michels |first5=Ralf |date=2016-10-14 |title=Refractive errors |journal=Deutsches Ärzteblatt International |volume=113 |issue=41 |pages=693–702 |doi=10.3238/arztebl.2016.0693 |pmid=27839543 |issn=1866-0452|pmc=5143802 }}</ref>