Modulation transfer functions in children: pupil size dependence and meridional anisotropy
Related Experiment Video
Updated: Sep 23, 2026
Assessing Pupil-linked Changes in Locus Coeruleus-mediated Arousal Elicited by Trigeminal Stimulation
Published on: November 26, 2019
Andrew Carkeet1, Seo-Wei Leo, Boo-Kian Khoo
1Singapore Eye Research Institute, Singapore. seri_acarkeet@snec.com.sg
Insights
Preschool children
Area of Science:
- Ophthalmic optics
- Pediatric vision science
Background:
- Understanding ocular optical quality in children is crucial for visual development.
- Limited data exists on preschool children's visual optics, particularly aberrations and modulation transfer function (MTF).
Purpose of the Study:
- To quantify preschool children's optical quality, including aberrations and MTF.
- To investigate how pupil size and grating orientation affect MTF in this age group.
Main Methods:
- Aberrometry was employed to measure Zernike coefficients in 34 Chinese preschool children (aged 4.95-6.89 years).
- Mathematical correction for refractive error was applied.
- Modulation transfer function (MTF) was calculated for pupil sizes from 1-5 mm and various grating orientations.
Main Results:
- Third-order aberrations predominated, with positive spherical aberration observed.
- Average MTFs were optimal at 3-mm pupil sizes and slightly superior to those in young adults.
- MTF was significantly related to higher-order root mean square (RMS) and showed slight meridional anisotropy.
Conclusions:
- Ocular optical quality in preschool children is dependent on pupil size.
- The optics exhibit slight meridional anisotropy.
- Optical quality in this age group is comparable to, or slightly better than, that of young adults.
Purpose:
This study quantified preschool children's optical quality in terms of their aberrations and modulation transfer function (MTF), and examined the dependence of MTF on pupil size and grating orientation.
Methods:
Aberrometry was used to measure Zernike coefficients in 34 Chinese preschool children (18 males, 16 females; aged 4.95-6.89 years; mean, 5.91 +/- 0.56). For each subject, after mathematical correction for refractive error, these wavefront errors were used to calculate MTF (lambda = 550 nm) for pupil sizes from 1 to 5 mm and for gratings at orientations in 15 degrees intervals.
Results:
Aberrations were correlated between right and left eyes, for wavefront RMS and some Zernike coefficients. Average aberrometry results showed that third-order terms predominated, in addition to some positive spherical aberration with an average higher order root mean square (RMS) of 0.20 micro m over a 5-mm pupil. Average MTFs were optimal for 3-mm pupil sizes at lower spatial frequencies (<69 cyc/deg) and slightly better than those found by similar techniques in young adults. Heights of MTFs were significantly related to higher order RMS (Spearman rho = -0.926). MTFs showed a small meridional anisotropy for 3-mm pupils, with average MTF for vertical gratings (horizontal modulation) being slightly, but significantly better than for horizontal gratings (vertical modulation). There was no evidence of an oblique effect in the optics of these children.
Conclusions:
In these children, ocular optical quality is pupil dependent, shows slight meridional anisotropy and is slightly better than that for young adults.
