Foveal crowding differs in children and adults

Yvonne Norgett, John Siderov

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We used custom-designed acuity tests to compare the magnitude and extent of crowded letter recognition in children and adults. Visual acuity (logMAR) was measured monocularly in children and adults using five custom-designed letter tests with varying degrees of crowding: single letter, single letter surrounded by four flanking bars, single letter surrounded by four flanking letters, line of five letters surrounded by flanking bars, and line of five letters surrounded by flanking letters. The tests were constructed using Sloan letters and presented on an iPad (Apple Incorporated, Cupertino, CA) at 4 m using a standardized endpoint and instructions. Crowded logMAR was normalized to unflanked logMAR and results were analyzed in three groups: younger children aged 4-6 (n = 32), older children, aged 7-9 (n = 30), and adults (n = 27). Both groups of children showed a greater extent of crowding than the adults. The adult participants showed no difference in performance between single or linear presentation and letter or bar flankers. Letter flankers and linear presentation individually resulted in poorer performance in the younger children p < 0.001 and p = 0.003, respectively (mean normalized logMAR 0.17 in each case) and together had an additive effect (mean 0.24), p < 0.001. Crowding in the older children was adult-like except in the linear presentation with letter flankers, p < 0.001. These results indicate that both target-flanker similarity and linear presentation contribute more to foveal crowding in young children than in adults.

LanguageEnglish
Article number23
JournalJournal of Vision
Volume14
Issue number12
DOIs
Publication statusPublished - 1 Oct 2014
Externally publishedYes

Fingerprint

Crowding
Malus
Visual Acuity

Cite this

@article{58f515940f3b421d9811aab76d26938c,
title = "Foveal crowding differs in children and adults",
abstract = "We used custom-designed acuity tests to compare the magnitude and extent of crowded letter recognition in children and adults. Visual acuity (logMAR) was measured monocularly in children and adults using five custom-designed letter tests with varying degrees of crowding: single letter, single letter surrounded by four flanking bars, single letter surrounded by four flanking letters, line of five letters surrounded by flanking bars, and line of five letters surrounded by flanking letters. The tests were constructed using Sloan letters and presented on an iPad (Apple Incorporated, Cupertino, CA) at 4 m using a standardized endpoint and instructions. Crowded logMAR was normalized to unflanked logMAR and results were analyzed in three groups: younger children aged 4-6 (n = 32), older children, aged 7-9 (n = 30), and adults (n = 27). Both groups of children showed a greater extent of crowding than the adults. The adult participants showed no difference in performance between single or linear presentation and letter or bar flankers. Letter flankers and linear presentation individually resulted in poorer performance in the younger children p < 0.001 and p = 0.003, respectively (mean normalized logMAR 0.17 in each case) and together had an additive effect (mean 0.24), p < 0.001. Crowding in the older children was adult-like except in the linear presentation with letter flankers, p < 0.001. These results indicate that both target-flanker similarity and linear presentation contribute more to foveal crowding in young children than in adults.",
keywords = "Children's vision, Crowding, Visual development",
author = "Yvonne Norgett and John Siderov",
year = "2014",
month = "10",
day = "1",
doi = "10.1167/14.12.23",
language = "English",
volume = "14",
journal = "Journal of Vision",
issn = "1534-7362",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "12",

}

Foveal crowding differs in children and adults. / Norgett, Yvonne; Siderov, John.

In: Journal of Vision, Vol. 14, No. 12, 23, 01.10.2014.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Foveal crowding differs in children and adults

AU - Norgett, Yvonne

AU - Siderov, John

PY - 2014/10/1

Y1 - 2014/10/1

N2 - We used custom-designed acuity tests to compare the magnitude and extent of crowded letter recognition in children and adults. Visual acuity (logMAR) was measured monocularly in children and adults using five custom-designed letter tests with varying degrees of crowding: single letter, single letter surrounded by four flanking bars, single letter surrounded by four flanking letters, line of five letters surrounded by flanking bars, and line of five letters surrounded by flanking letters. The tests were constructed using Sloan letters and presented on an iPad (Apple Incorporated, Cupertino, CA) at 4 m using a standardized endpoint and instructions. Crowded logMAR was normalized to unflanked logMAR and results were analyzed in three groups: younger children aged 4-6 (n = 32), older children, aged 7-9 (n = 30), and adults (n = 27). Both groups of children showed a greater extent of crowding than the adults. The adult participants showed no difference in performance between single or linear presentation and letter or bar flankers. Letter flankers and linear presentation individually resulted in poorer performance in the younger children p < 0.001 and p = 0.003, respectively (mean normalized logMAR 0.17 in each case) and together had an additive effect (mean 0.24), p < 0.001. Crowding in the older children was adult-like except in the linear presentation with letter flankers, p < 0.001. These results indicate that both target-flanker similarity and linear presentation contribute more to foveal crowding in young children than in adults.

AB - We used custom-designed acuity tests to compare the magnitude and extent of crowded letter recognition in children and adults. Visual acuity (logMAR) was measured monocularly in children and adults using five custom-designed letter tests with varying degrees of crowding: single letter, single letter surrounded by four flanking bars, single letter surrounded by four flanking letters, line of five letters surrounded by flanking bars, and line of five letters surrounded by flanking letters. The tests were constructed using Sloan letters and presented on an iPad (Apple Incorporated, Cupertino, CA) at 4 m using a standardized endpoint and instructions. Crowded logMAR was normalized to unflanked logMAR and results were analyzed in three groups: younger children aged 4-6 (n = 32), older children, aged 7-9 (n = 30), and adults (n = 27). Both groups of children showed a greater extent of crowding than the adults. The adult participants showed no difference in performance between single or linear presentation and letter or bar flankers. Letter flankers and linear presentation individually resulted in poorer performance in the younger children p < 0.001 and p = 0.003, respectively (mean normalized logMAR 0.17 in each case) and together had an additive effect (mean 0.24), p < 0.001. Crowding in the older children was adult-like except in the linear presentation with letter flankers, p < 0.001. These results indicate that both target-flanker similarity and linear presentation contribute more to foveal crowding in young children than in adults.

KW - Children's vision

KW - Crowding

KW - Visual development

UR - http://www.scopus.com/inward/record.url?scp=84916214699&partnerID=8YFLogxK

U2 - 10.1167/14.12.23

DO - 10.1167/14.12.23

M3 - Article

VL - 14

JO - Journal of Vision

T2 - Journal of Vision

JF - Journal of Vision

SN - 1534-7362

IS - 12

M1 - 23

ER -