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Updated: May 7, 2026
07:06
Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients
Published on: March 29, 2022
Hyperopic defocus and diurnal changes in human choroid and axial length
Ranjay Chakraborty1, Scott A Read, Michael J Collins
1*BS(Optom) †PhD, FAAO Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology (QUT), Kelvin Grove, Brisbane, Queensland, Australia.
Summary
Monocular hyperopic defocus significantly increased diurnal changes in young adults' axial length and choroidal thickness. These changes returned to normal the day after removing the blur stimulus, indicating a reversible effect.
Area of Science:
- Ophthalmology
- Physiological Optics
Background:
- Diurnal rhythms in ocular parameters are crucial for understanding eye growth and health.
- Investigating the impact of altered visual stimuli on these rhythms provides insights into ocular development and adaptation.
Purpose of the Study:
- To determine how monocular hyperopic defocus affects the natural diurnal variations in axial length and choroidal thickness in young adults.
Main Methods:
- 15 emmetropic young adults underwent axial length and choroidal thickness measurements every ~3 hours for three days.
- Day 1: Natural diurnal rhythms. Day 2: Monocular hyperopic defocus (-2.00 DS) in the right eye. Day 3: Recovery without defocus.
Main Results:
- Both axial length and choroidal thickness exhibited significant diurnal changes daily (p < 0.0001).
- Monocular hyperopic defocus significantly altered diurnal variations (p < 0.05), increasing the amplitude of change in axial length (0.016 ± 0.005 mm) and choroidal thickness (0.011 ± 0.003 mm) on day 2.
- The eye became significantly longer (0.012 ± 0.002 mm) at midday with defocus compared to control days (p < 0.05).
Conclusions:
- Monocular hyperopic defocus significantly amplifies diurnal fluctuations in axial length and choroidal thickness.
- These induced changes are reversible, normalizing the day after the defocus stimulus is removed.
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