This study will examine the accommodative behavior in children undergoing myopia control treatments. A subset of children showing reduced accommodation, known to occur in while wearing multifocal soft contact lenses (MFCL) from previous studies, will undergo auditory biofeedback training to improve the accommodative response and possibly improve treatment efficacy. The results of this study will be used to design a larger clinical trial.

Aim 1 - The accommodation response in myopic children being treated with MFCL for six months or longer, will be determined. The accommodative response data will be collected while the patients are wearing the MFCL and will be compared to the baseline control response when the subjects wear single vision soft contact lenses (SVCL). Additional comparisons will include accommodative measures in untreated myopic children wearing spectacle corrections (unttreated controls), children being treated with ortho-keratology contact lenses, and children treated with low-dose atropine (0.01%, considered not to affect accommodation). How these additional myopia treatments affect the accommodation response has yet to be determined.

Aim 2 - Children treated with MFCL who show reduced accommodative responses will undergo a brief period of auditory biofeedback accommodative training to determine whether the response in children can be improved and how long it can be sustained. Improving the accommodative response in these patients may improve the treatment efficacy by increasing the effect of the positive power addition built into the lenses.

Inclusion Criteria:

• Best corrected monocular Snellen visual acuity (VA) ≧ 20/25
• Age 8 - 15 years
• Refractive error spherical equivalent between -0.75 D and -10 D
• Astigmatism ≤ 0.75 D
• Age-appropriate amplitude of accommodation
• No suspected or confirmed eye disease (anamnesis)
• No accommodative or binocular function abnormalities
• Agreement to participate in the study (informed consent of parents, assent of child)
• Children who are currently under myopia control treatment should already be so for ≥ 6 months

Exclusion Criteria:

• Persons who are incapable of giving consent
• Refractive error spherical equivalent < -10 D and > -0.75 D
• Astigmatism > 0.75 D
• Abnormal binocular functions
• Medication affecting accommodative response or causing dry eye

Pediatric population