Retinal scan
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2008-05-07T07:01:05Z
146.186.149.139
/* Uses */
A '''retinal scan''' is a [[biometric]] technique that uses the unique patterns on a person's [[retina]] to identify them. It is not to be confused with another ocular-based technology, [[iris recognition]].
== Introduction ==
The [[human]] retina is a thin [[Tissue (biology)|tissue]] composed of [[Nerve|neural cells]] that is located in the posterior portion of the [[eye]]. Because of the complex structure of the [[Capillary|capillaries]] that supply the retina with [[blood]], each person's retina is unique. The network of [[blood vessel]]s in the retina is so complex that [[identical twin]]s do not even share a similar pattern.
Although retinal patterns may be altered in cases of [[diabetes]], [[glaucoma]], retinal degenerative disorders or [[cataracts]], the retina typically remains unchanged from birth until death. Due to its unique and unchanging nature, the retina appears to be the most precise and reliable biometric.<ref>Retina and Iris Scans. Encyclopedia of Espionage, Intelligence, and Security. Copyright © 2004 by The Gale Group, Inc.</ref> Advocates of retinal scanning have concluded that it is so accurate that its error rate is estimated to be only one in a million.
A [[biometric]] identifier known as a '''retinal scan''' is used to map the unique patterns of a person's [[retina]]. The [[blood vessels]] within the [[retina]] absorb light more readily than the surrounding tissue and are easily identified with appropriate lighting. A retinal scan is performed by casting an undetectable ray of low-energy [[infrared light]] into a person’s eye as they look through the scanner's eyepiece. This beam of light outlines a circular path on the retina. Because retinal blood vessels are more sensitive to light than the rest of the eye, the amount of reflection fluctuates. The results of the scan are converted to computer code and stored in a [[database]].<ref>[http://www.discoveriesinmedicine.com/Ra-Thy/Retinography.html Retinography: How Retinal Scanning Works.] Retrieved on 2007-04-02.</ref>
== History ==
The idea for retinal identification was first conceived by Dr. Carleton Simon and Dr. Isodore Goldstein and was published in the New York State Journal of Medicine in [[1935]]<ref>[http://www.time.com/time/printout/0,8816,755453,00.html “Eye Prints,” TIME Magazine, Dec. 16, 1935]. Retrieved on 2008-04-10.</ref>. The idea was a little before its time, but once [[technology]] caught up, the concept for a retinal scanning device emerged in [[1975]]. In [[1976]], Robert "Buzz" Hill formed a corporation named EyeDentify, Inc., and made a full-time effort to research and develop such a device. In [[1978]], the idea of a retinal scanner was patented, followed by a practical working prototype in [[1981]].<ref>Hill, Robert. [http://www.cse.msu.edu/~cse891/Sect601/textbook/6.pdf “Retina Identification”.] Msu.Edu. Retrieved on 2007-04-02</ref>
== Uses ==
Retinal scanners are typically used for authentication and identification purposes. Retinal scanning has been utilized by several government agencies including the [[FBI]], [[CIA]], and [[NASA]]. However, in recent years, retinal scanning has become more commercially popular. Retinal scanning has been used in prisons, for [[Automated teller machine|ATM]] identity verification and the prevention of [[Welfare (financial aid)|welfare]] fraud.<ref>[http://et.wcu.edu/aidc/BioWebPages/Biometrics_Eye.html Iris/Retinal Identification.] Wcu.Edu. Retrieved on 2007-04-02.</ref>
Retinal scanning also has medical applications. Communicable illnesses such as [[AIDS]], [[syphilis]], [[malaria]], [[chicken pox]] and [[Lyme disease]] as well as [[hereditary disease]]s like [[leukemia]], [[lymphoma]], and [[sickle cell anemia]] impact the eyes. [[Pregnancy]] also affects the eyes. Likewise, indications of chronic health conditions such as [[congestive heart failure]], [[atherosclerosis]], and [[cholesterol]] issues first appear in the eyes.<ref>Ostaff, Courtney. [http://www.physorg.com/news6134.html “Retinal Scans Do More than Let You in Door."] Retrieved on 2007-04-02.</ref>
== Pros and Cons ==
'''Advantages'''<sup>[4]</sup> <br />
* Low occurrence of false negatives <br />
* Extremely low (almost 0%) false positive rates<br />
* Highly reliable because no two people have the same retinal pattern<br />
* Speedy results: Identity of the subject is verified very quickly<br />
'''Disadvantages'''<sup>[4]</sup><ref>Roberts, Chris. [http://www.ccip.govt.nz/ccip-publications/ccip-reports/Biometrics.pdf "Biometrics"] Retrieved on 2007-04-02.</ref><br />
* Measurement accuracy can be affected by diseases such as [[cataracts]] and [[glaucoma]] <br />
* Scanning procedure is highly invasive <br />
* Not very user friendly<br />
* Limited government, corporate, and other funding <br />
* Subject being scanned must focus on the scanner from about three inches away<br />
* High equipment costs<br />
* Poor lighting can affect results
* Retinal vessel pattern can change with systemic and other ocular disease, especially diabetes and hypertension.<br />
==References==
<references/>
[[Category:Biometrics]]
[[gl: Retina, Identificación biométrica]]