Combination Effect of Optical Defocus and Low Dose Atropine in Myopia Control

Inclusion Criteria: * Age at enrollment: 7 to 12 years * Ethnicity: Hong Kong Chinese * Myopia: -0.75D (in spherical equivalent) or above in both eyes * Astigmatism: -1.50D or less in both eyes * Anisometropia: 1.50D or less (in spherical equivalent) between two eyes * Best corrected monocular visual acuity (VA): 0.04 logMAR or better * Ocular health: No abnormalities in both internal and external ocular health * Systemic health: No abnormalities such as cardiac and respiratory diseases * Binocular vision: No strabismus, diplopia, suppression and other binocular abnormalities * Normal colour vision * No previous refractive surgery or use of myopic control interventions, such as atropine, orthokeratology, and specialized spectacle lenses and contact lenses for myopic control * Able to wear the prescribed spectacles * No known allergy to atropine Exclusion Criteria: * Eye disease or binocular vision problems (e.g., strabismus, amblyopia, oculomotor nerve palsies, corneal disease, etc.) * Previous intraocular or corneal surgery * Colour vision deficiencies * Systemic disease that may affect vision, vision development (e.g. diabetes mellitus, hypertension, Down syndrome, etc.) * Systemic disease that are contradictory to atropine (e.g. asthma, cardiac diseases, etc.) * Previous gas permeable, soft bifocal, or orthokeratology contact lenses wear or bifocal / progressive addition lens spectacles wear or use of atropine or pirenzepine (longer than one month of usage) * Previous or current participation in myopia control studies * Allergy to cyclopentolate hydrochloride or atropine