Accommodation and Acuity in the Human Infant
Part of the
NATO Advanced Study Institutes Series
book series (NSSA, volume 27)
Our studies using behavioural (preferential looking) and evoked-potential techniques indicate a rapid development of acuity and contrast sensitivity over the first six months of life. The technique of “photorefraction” allows us to measure how accurately the infant’s eyes are optically focused over a range of distances, and hence to investigate whether the infant’s performance is limited by optical or by neural development. We find that most infants of 1 month and older accommodate accurately at distances up to 75 cm, but that accommodation at 150 cm is not accurate until later than 3 months of age. However, many newborn and 1-month infants show inconsistent fluctuations of accommodation over the whole range, indicating the physical capability to accommodate.
The errors of accommodation in young infants are not large enough to account for the low acuity; acuity appears to be determined by the development of the visual pathway.
Sixty percent of infants under 1 year are significantly astigmatic. This finding may have implications for the plasticity of the human visual system in early life.
KeywordsContrast Sensitivity Human Visual System Modulation Transfer Function Human Infant Pupil Size
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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