Difference between revisions of Blur

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= 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 myopic defocus is protective against myopia progression and can induce axial lengthening and shortening.
The eye needs stimulus to make corrective changes.  Studies have shown that inducing defocus can induce axial lengthening and shortening.
 
<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>
{{cite web paper |url=https://www.pum.edu.pl/__data/assets/pdf_file/0007/112849/PomeranianJLifeSci_62-01_025-030.pdf |title=Long -term effects of optical defocus on eye growth and refractogenesis |publisher=Pomeranian J Life Sci ||author=Elena Tarutta, Narine Khodzhabekyan, Oksana Filinova, Sergei Milash, Galina Kruzhkova |year=2016}}
 
{{cite web paper |url=https://iovs.arvojournals.org/article.aspx?articleid=2189093 |title=Eyes in Various Species Can Shorten to Compensate for Myopic Defocus |publisher=Anatomy and Pathology/Oncology ||author=Xiaoying Zhu; Neville A. McBrien; Earl L. Smith, III; David Troilo; Josh Wallman |year=2013}}


= EM Blur Adaption =
= EM Blur Adaption =

Revision as of 04:18, 1 June 2020

What is Blur

There are many sources of failure to recognize characters, blur is the only one addressed by EM. Blur is when the edges of the thing you are looking at is not well defined. Print may be too small to see without being blurry. A normal healthy eye can experience blur by looking through a lens not designed for it.

Myopic vs Hyperopic Blur

Myopic blur is the type of blur normally experienced by people with uncompensated myopia. Hyperopic blur is the type normally experienced by people with uncompensated hyperopia. In order to induce blur, use a lens with the opposite diopter sign as the lens normally used for blur correction, so a plus lens will give myopic blur to an emmetrope. A weak negative lens will give myopic blur to a myope.

Studies show that extreme hyperopic blur conditions induce myopia in growing animals, and myopic blur in growing myopic animals can partially reverse this.

To format properly later: Proteomic analysis of chick retina during early recovery from lens‑induced myopia - Yun Yun Zhou et al. - May 3, 2018 https://www.spandidos-publications.com/mmr/18/1/59?text=fulltext

Diffusion blur

Diffusion such as frosted glass, causes myopia just as strong myopic lenses do in growing animals. This is also called form deprivation.

Directional blur

Text appears smeared in a direction. This is the defining symptom of astigmatism

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. [1][2]

EM Blur Adaption

"Blur Adaption" unfortunately has two meanings. The meaning commonly meant by EM forum members is encountering so much blur that your eye no longer tried to accommodate the blur. This is something like learned helplessness at the biological level.

Clinical Blur Adaption

When a doctor uses the term "Blur Adaption" they mean that a person has adapted to perform visual tasks despite their blur. This is almost the opposite of EM blur adaption.

See Also

External sources

https://www.sciencedirect.com/science/article/pii/S0042698906005621 - Conceptual model of human blur perception

References

  1. Tarutta, Elena (2016). "Long -term effects of optical defocus on eye growth and refractogenesis" (PDF). Pomeranian J Life Sci.Page Module:Citation/CS1/styles.css has no content.
  2. Zhu, Xiaoying; McBrien, Neville A.; Smith, Earl L.; Troilo, David; Wallman, Josh (2013-04-01). "Eyes in Various Species Can Shorten to Compensate for Myopic Defocus". Investigative Ophthalmology & Visual Science. 54 (4): 2634–2644. doi:10.1167/iovs.12-10514. ISSN 1552-5783.Page Module:Citation/CS1/styles.css has no content.