Carkeet A, Levi D M, Manny R E
Department of Optometry and Vision Science, University of Auckland, New Zealand.
Optom Vis Sci. 1997 Sep;74(9):741-50. doi: 10.1097/00006324-199709000-00022.
To measure Vernier acuity and resolution development after 3 years of age.
Observers were 39 children with normal vision (aged 3 to 12 years), 10 adult observers with normal vision (aged 19 to 24 years), and 7 adults with amblyopia. Vernier acuity and resolution were measured using uncrowded static stimuli and a 3AFC psychophysical paradigm. Curve fitting was used to estimate A2, the age at which thresholds are twice asymptotic levels.
Vernier acuity was hyperacute (i.e., finger than predicted from foveal cone size or spacing) in 3- to 4-year-old observers, but developed later (A2 = 5.6 +/- 1.5 years) than resolution acuity (A2 = 2.2 +/- 0.9 years).
Children's Vernier thresholds are poorer than would be predicted solely from their decreased foveal photon capture. Therefore cortical immaturity may play a role in children's relative position acuity deficit. R/V ratios (resolution/Vernier thresholds) for the youngest age group are similar to those for adult nonstrabismic amblyopes, but better than for strabismic amblyopes.
测量3岁以后的游标视力和分辨力发育情况。
观察者包括39名视力正常的儿童（年龄3至12岁）、10名视力正常的成年观察者（年龄19至24岁）以及7名弱视成年人。使用未拥挤的静态刺激和3AFC心理物理学范式测量游标视力和分辨力。采用曲线拟合来估计A2，即阈值为渐近水平两倍时的年龄。
3至4岁的观察者游标视力超敏锐（即比根据中央凹视锥细胞大小或间距预测的更敏锐），但其发育时间比分辨力视力晚（A2 = 5.6 ± 1.5岁）（分辨力视力的A2 = 2.2 ± 0.9岁）。
儿童的游标视力阈值比仅根据其中央凹光子捕获减少所预测的要差。因此，皮质不成熟可能在儿童相对位置视力缺陷中起作用。最年幼年龄组的R/V比率（分辨力/游标视力阈值）与成年非斜视性弱视患者相似，但优于斜视性弱视患者。
