Effects of Induced Optical Blur on Infant Visal Acuity

Boltz, Roger L.; Manny, Ruth E.; Katz, Beverley J.

doi:10.1097/00006324-198302000-00002

Cited by 8 publications

(4 citation statements)

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“…Particularly important is the relationship between VA and the refractive state of the eye 1, 2, 3, 4. However, VA is affected by different extrinsic parameters, such as the design of the optotype chart, its luminance and contrast, since these factors can affect the chart readability 5, 6.…”

Section: Introductionmentioning

confidence: 99%

Influence of different types of astigmatism on visual acuity

Remón

Monsoriu

Furlan

2017

Journal of Optometry

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PurposeTo investigate the change in visual acuity (VA) produced by different types of astigmatism (on the basis of the refractive power and position of the principal meridians) on normal accommodating eyes.MethodsThe lens induced method was employed to simulate a set of 28 astigmatic blur conditions on different healthy emmetropic eyes. Additionally, 24 values of spherical defocus were also simulated on the same eyes for comparison. VA was measured in each case and the results, expressed in logMAR units, were represented against of the modulus of the dioptric power vector (blur strength).ResultsLogMAR VA varies in a linear fashion with increasing astigmatic blur, being the slope of the line dependent on the accommodative demand in each type of astigmatism. However, in each case, we found no statistically significant differences between the three axes investigated (0°, 45°, 90°). Non-statistically significant differences were found either for the VA achieved with spherical myopic defocus (MD) and mixed astigmatism (MA). VA with simple hyperopic astigmatism (SHA) was higher than with simple myopic astigmatism (SMA), however, in this case non conclusive results were obtained in terms of statistical significance. The VA achieved with imposed compound hyperopic astigmatism (CHA) was highly influenced by the eye's accommodative response.ConclusionsVA is correlated with the blur strength in a different way for each type of astigmatism, depending on the accommodative demand. VA is better when one of the focal lines lie on the retina irrespective of the axis orientation; accommodation favors this situation.

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Section: Introductionmentioning

confidence: 99%

Influence of different types of astigmatism on visual acuity

Remón

Monsoriu

Furlan

2017

Journal of Optometry

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“…Atkinson et al 19 showed that 1-to 3-month-old infants could discriminate behaviorally between blurred and sharp images. Two other studies also demonstrated that infants' visual acuity could be reduced by introducing lenses of as little as 1 to 2 D. 20,21 These studies are limited in the context of analyses of accommodative performance, however, in that they did not control or measure accommodation, and therefore the data cannot be interpreted in the terms of sensitivity to absolute change in retinal defocus.…”

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confidence: 99%

The Sensitivity of the 2- to 4-Month-Old Human Infant Accommodation System

Wang

Candy

2010

Invest. Ophthalmol. Vis. Sci.

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“…1,2 Several studies have described the effects on VA of spherocylindrical refractive errors. [3][4][5][6][7] In 1961, Peters 3 investigated the relation between VA and uncompensated ocular defocus. He developed charts of iso-oxyopia (lines of equal acuity) that gave expected VA in eyes of different uncompensated refractive states.…”

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confidence: 99%