Effect of Biofeedback Training on Accommodation During Multifocal Lens Wear in Young Adults

This study will examine the accommodative behavior in young adults wearing multifocal soft contact lenses. undergoing myopia control treatments. Subjects will undergo auditory biofeedback training while wearing the multifocal contact lenses to improve the accommodative. This pilot study is divided into three separate experiments and aims to assess:the time course of the effect of biofeedback training in young adults wearing MFCLs -- the time course groupwhether repeated biofeedback training increases the efficacy in young adults wearing MFCLs -- the repetition groupwhether a longer training duration, given repeatedly, increases the efficacy in young adults wearing MFCLs -- the longer duration groupThe results of this study will be used to design a larger clinical trial to investigate whether increasing accommodative responses through the multifocal contact lenses increases multifocal lenses' treatment effect on myopia management in children.

Inclusion Criteria:Best corrected monocular Snellen visual acuity (VA) ≧ 20/25Age 18 to 30 yearsRefractive error spherical equivalent between -0.75 D and -10 DAstigmatism ≤ 0.75 DAge-appropriate amplitude of accommodationNo suspected or confirmed eye disease (anamnesis)No accommodative or binocular function abnormalitiesAgreement to participate in the study (informed consent of subjects)Exclusion Criteria:Persons who are incapable of giving consentRefractive error spherical equivalent < -10 D and > -0.75 DAstigmatism > 0.75 DAbnormal binocular functionsMedication affecting accommodative response or causing dry eye