{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T07:49:53Z","timestamp":1774943393002,"version":"3.50.1"},"reference-count":28,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2011,5,1]],"date-time":"2011-05-01T00:00:00Z","timestamp":1304208000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2011,5,1]],"date-time":"2011-05-01T00:00:00Z","timestamp":1304208000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["OVS"],"published-print":{"date-parts":[[2011,5]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose.<\/jats:title>\n                    <jats:p>To compare the effects of \u201csimulated\u201d and \u201creal\u201d spherical and astigmatic defocus on visual acuity (VA).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods.<\/jats:title>\n                    <jats:p>VA was determined with letter charts that were blurred by calculated spherical or astigmatic defocus (simulated defocus) or were seen through spherical or astigmatic trial lenses (real defocus). Defocus was simulated using ZEMAX and the Liou\u2010Brennan eye model. Nine subjects participated [mean age, 27.2 \u00b1 1.8 years; logarithm of the minimum angle of resolution (logMAR), \u22120.1]. Three different experiments were conducted in which VA was reduced by 20% (logMAR 0.0), 50% (logMAR 0.2), or 75% (logMAR 0.5) by either (1) imposing positive spherical defocus, (2) imposing positive and negative astigmatic defocus in three axes (0, 45, and 90\u00b0), and (3) imposing cross\u2010cylinder defocus in the same three axes as in (2).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results.<\/jats:title>\n                    <jats:p>Experiment (1): there were only minor differences in VA with simulated and real positive spherical defocus. Experiment (2): simulated astigmatic defocus reduced VA twice as much as real astigmatic defocus in all tested axes (p &lt; 0.01 in all cases). Experiment (3): simulated cross\u2010cylinder defocus reduced VA much more than real cross\u2010cylinder defocus (p &lt; 0.01 in all cases), similarly for all three tested axes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions.<\/jats:title>\n                    <jats:p>The visual system appears more tolerant against \u201creal\u201d spherical, astigmatic, and cross\u2010cylinder defocus than against \u201csimulated\u201d blur. Possible reasons could be (1) limitations in the modeling procedures to simulate defocus, (2) higher ocular aberrations, and (3) fluctuations of accommodation. However, the two optical explanations (2) and (3) cannot account for the magnitude of the effect, and (1) was carefully analyzed. It is proposed that something may be special about the visual processing of real astigmatic and cross\u2010cylinder defocus\u2014because they have less effect on VA than simulations predict.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1097\/opx.0b013e31821281bc","type":"journal-article","created":{"date-parts":[[2011,4,1]],"date-time":"2011-04-01T05:54:55Z","timestamp":1301637295000},"page":"562-569","source":"Crossref","is-referenced-by-count":41,"title":["Visual Acuity with Simulated and Real Astigmatic Defocus"],"prefix":"10.1002","volume":"88","author":[{"given":"Arne","family":"Ohlendorf","sequence":"first","affiliation":[{"name":"University Eye Hospital T\u00fcbingen Institute for Ophthalmic Research Section of Neurobiology of the Eye T\u00fcbingen Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juan","family":"Tabernero","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica Laboratorio de Optica Universidad de Murcia Campus de Espinardo(Edificio CiOyN) Murcia Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Frank","family":"Schaeffel","sequence":"additional","affiliation":[{"name":"University Eye Hospital T\u00fcbingen Institute for Ophthalmic Research Section of Neurobiology of the Eye T\u00fcbingen Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2011,5,1]]},"reference":[{"key":"e_1_2_7_2_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.preteyeres.2004.06.004","article-title":"How genetic is school myopia?","volume":"24","author":"Morgan I","year":"2005","journal-title":"Prog Retin Eye Res"},{"key":"e_1_2_7_3_2","first-page":"1232","article-title":"Genes and environment in refractive error: the twin eye study","volume":"42","author":"Hammond CJ","year":"2001","journal-title":"Invest Ophthalmol Vis 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