Difference between revisions of Blur
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Dlskidmore (talk | contribs) m (adding some of the other defocus definitions being discussed on the forum.) |
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==Directional blur== | ==Directional blur== | ||
Text appears smeared in a direction. This is the defining symptom of [[astigmatism]] | Text appears smeared in a direction. This is the defining symptom of [[astigmatism]] | ||
==Peripheral Blur== | |||
Peripheral blur is the blurring of the part of the image outside your center of focus. This happens normally when something to the side is at a different distance than the thing you're looking at. While wearing glasses this becomes more complex because the outside of your lenses are often stronger than the center of focus, and produce hyperopic blur (which may be a contributor to lens induced myopia). | |||
==Defocus as a stimulus for [[accommodation]]== | |||
The [[lens]] in your eye is adjustable to try to compensate for moderate amounts of blur. As your eye experiences Defocus, the short term response is to move the lens in the direction needed to correct for that blur. | |||
==Defocus as a stimulus for eye length changes== | ==Defocus as a stimulus for eye length changes== | ||
The eye needs stimulus to make corrective changes. Studies have shown that inducing defocus can induce axial lengthening and shortening. | The eye needs stimulus to make long term corrective changes. Studies have shown that inducing defocus can induce axial lengthening and shortening. | ||
<ref name="pmid29749514">{{cite journal| author=Zhou YY, Chun RKM, Wang JC, Zuo B, Li KK, Lam TC | display-authors=etal| title=Proteomic analysis of chick retina during early recovery from lens‑induced myopia. | journal=Mol Med Rep | year= 2018 | volume= 18 | issue= 1 | pages= 59-66 | pmid=29749514 | doi=10.3892/mmr.2018.8954 | pmc=6059693 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=29749514 }} </ref> | <ref name="pmid29749514">{{cite journal| author=Zhou YY, Chun RKM, Wang JC, Zuo B, Li KK, Lam TC | display-authors=etal| title=Proteomic analysis of chick retina during early recovery from lens‑induced myopia. | journal=Mol Med Rep | year= 2018 | volume= 18 | issue= 1 | pages= 59-66 | pmid=29749514 | doi=10.3892/mmr.2018.8954 | pmc=6059693 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=29749514 }} </ref> | ||
<ref>{{Cite journal |last=Tarutta |first=Elena |date=2016 |title=Long -term effects of optical defocus on eye growth and refractogenesis |url=https://www.pum.edu.pl/__data/assets/pdf_file/0007/112849/PomeranianJLifeSci_62-01_025-030.pdf |journal=Pomeranian J Life Sci}}</ref><ref>{{Cite journal |last=Zhu |first=Xiaoying |last2=McBrien |first2=Neville A. |last3=Smith |first3=Earl L. |last4=Troilo |first4=David |last5=Wallman |first5=Josh |date=2013-04-01 |title=Eyes in Various Species Can Shorten to Compensate for Myopic Defocus |url=https://iovs.arvojournals.org/article.aspx?articleid=2189093 |journal=Investigative Ophthalmology & Visual Science |language=en |volume=54 |issue=4 |pages=2634–2644 |doi=10.1167/iovs.12-10514 |issn=1552-5783}}</ref> | <ref>{{Cite journal |last=Tarutta |first=Elena |date=2016 |title=Long -term effects of optical defocus on eye growth and refractogenesis |url=https://www.pum.edu.pl/__data/assets/pdf_file/0007/112849/PomeranianJLifeSci_62-01_025-030.pdf |journal=Pomeranian J Life Sci}}</ref><ref>{{Cite journal |last=Zhu |first=Xiaoying |last2=McBrien |first2=Neville A. |last3=Smith |first3=Earl L. |last4=Troilo |first4=David |last5=Wallman |first5=Josh |date=2013-04-01 |title=Eyes in Various Species Can Shorten to Compensate for Myopic Defocus |url=https://iovs.arvojournals.org/article.aspx?articleid=2189093 |journal=Investigative Ophthalmology & Visual Science |language=en |volume=54 |issue=4 |pages=2634–2644 |doi=10.1167/iovs.12-10514 |issn=1552-5783}}</ref> | ||