Web-based visual acuity testing for children

Visual acuity measurement is an essential component of any eye exam. In adults and older children, letter-based acuity (i.e., recognition acuity) is commonly used to measure vision. However, in infants and toddlers, performing traditional visual acuity testing is nearly impossible. Instead, modified optotypes such as gratings and pictures are shown to observe the young child's visual behavior. Additionally, there are objective visual acuity methods that negate the need for observing visual behavior. For the practicing clinician, the choices are many and can be confusing. With new commercial products coming into the market every day, it is nearly impossible to comprehensively cover each one of them. Instead, in this chapter, commonly used and/or studied visual acuity tests are covered. For each test, the set-up, procedure, documentation, and scientific evidence supporting or negating its use are discussed.

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Parent-administered visual acuity testing: Is it reliable and can it improve office efficiency?

Journal of American Association for Pediatric Ophthalmology and Strabismus ◽

10.1016/j.jaapos.2004.02.004 ◽

2004 ◽

Vol 8 (4) ◽

pp. 332-337 ◽

Cited By ~ 2

Author(s):

Evelyn A. Paysse ◽

Larissa Camejo ◽

Mohamed A.W. Hussein ◽

David K. Coats

Keyword(s):

Visual Acuity ◽

Visual Acuity Testing

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Assessment of the Catford drum in visual acuity testing and its use as a measurement of visual performance in low-vision patients.

British Journal of Ophthalmology ◽

10.1136/bjo.71.10.797 ◽

1987 ◽

Vol 71 (10) ◽

pp. 797-802 ◽

Cited By ~ 2

Author(s):

J. J. Boop ◽

J. T. van Dalen ◽

G. S. Tyner

Keyword(s):

Visual Acuity ◽

Low Vision ◽

Visual Performance ◽

Visual Acuity Testing

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Foveal visual acuity is worse and shows stronger contour interaction effects for contrast-modulated than luminance-modulated Cs

Visual Neuroscience ◽

10.1017/s0952523813000102 ◽

2013 ◽

Vol 30 (3) ◽

pp. 105-120 ◽

Cited By ~ 4

Author(s):

MOHD IZZUDDIN HAIROL ◽

MONIKA A. FORMANKIEWICZ ◽

SARAH J. WAUGH

Keyword(s):

Visual Acuity ◽

Spatial Scales ◽

Receptive Fields ◽

Spatial Vision ◽

Interaction Effects ◽

Foveal Vision ◽

Spatial Mechanisms ◽

Visual Acuity Testing ◽

Contour Interaction ◽

Gap Width

AbstractContrast-modulated (CM) stimuli are processed by spatial mechanisms that operate at larger spatial scales than those processing luminance-modulated (LM) stimuli and may be more prone to deficits in developing, amblyopic, and aging visual systems. Understanding neural mechanisms of contour interaction or crowding will help in detecting disorders of spatial vision. In this study, contour interaction effects on visual acuity for LM and CM C and bar stimuli are assessed in normal foveal vision. In Experiment 1, visual acuity is measured for all-LM and all-CM stimuli, at ∼3.5× above their respective modulation thresholds. In Experiment 2, visual acuity is measured for Cs and bars of different type (LM C with CM bars and vice versa). Visual acuity is degraded for CM compared with LM Cs (0.46 ± 0.04 logMAR vs. 0.18 ± 0.04 logMAR). With nearby bars, CM acuity is degraded further (0.23 ± 0.01 logMAR or ∼2 lines on an acuity chart), significantly more than LM acuity (0.11 ± 0.01 logMAR, ∼1 line). Contour interaction for CM stimuli extends over greater distances (arcmin) than it does for LM stimuli, but extents are similar with respect to acuities (∼3.5× the C gap width). Contour interaction is evident when the Cs and bars are defined differently: it is stronger when an LM C is flanked by CM bars (0.17 ± 0.03 logMAR) than when a CM C is flanked by LM bars (0.08 ± 0.02 logMAR). Our results suggest that contour interaction for foveally viewed acuity stimuli involves feature integration, such that the outputs of receptive fields representing Cs and bars are combined. Contour interaction operates at LM and CM representational stages, it can occur across stage, and it is enhanced at the CM stage. Greater contour interaction for CM Cs and bars could hold value for visual acuity testing and earlier diagnosis of conditions for which crowding is important, such as in amblyopia.

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