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Accommodation in infants as measured by photorefraction
H C Howland1, V Dobson, N Sayles
1Section of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853.
Vision Research
|January 1, 1987
Summary
Infant vision accommodation was measured using a new video camera method. Infants adjusted focus appropriately for different distances, showing accommodation speeds similar to adults.
Area of Science:
- Ophthalmology
- Developmental Neuroscience
- Vision Science
Background:
- Accurate visual focus (accommodation) is crucial for infant visual development.
- Previous methods for measuring infant accommodation were limited.
Purpose of the Study:
- To develop and validate a non-invasive video camera photorefractive procedure for on-line monitoring of infant accommodation.
- To investigate infant accommodation responses to various visual targets at different distances.
Main Methods:
- A novel video camera photorefractive technique was employed for remote accommodation measurement (1-2m).
- Twenty-nine infants (2-10 months) were tested with square wave gratings and checkerboard targets at distances from 25cm to 100cm.
- Infants were also exposed to a slowly rotating striped target to assess responses to motion and astigmatism.
Main Results:
- All infants demonstrated appropriate accommodative responses to changes in target distance.
- Infant accommodation speeds reached at least 4.6 Diopters/second, comparable to adult capabilities.
- No systematic accommodative changes were observed in response to the rotating striped target or target type in astigmatic infants.
Conclusions:
- The developed video camera method effectively monitors infant accommodation.
- Infants exhibit robust and adult-like accommodation abilities from an early age.
- Further research is needed to understand specific accommodative responses in infants with astigmatism.