A Controlled Evaluation of Optical Defocus Parameters on Transient Changes in Axial Length Using Kubota Glass

Inclusion Criteria: * Be of legal age or, if under legal age have written consent of their parent or guardian to participate. * Sign written Informed Consent (and the California Bill of Rights, if applicable). * Be between age 8-24 (inclusive) and able to understand and assent to participation. * Have a spherical component of spectacle prescription between -1.00 and -5.00 diopters (D) (inclusive) in each eye. * Have a refractive astigmatism of less than or equal to -1.00 D in each eye. * Have axial length between 23.00 and 25.99 millimeters (mm) in each eye. * Best Spectacle Corrected Visual Acuity (BSCVA) of 20/25 or better in each eye. * Be willing and able to follow instructions and attend the schedule of follow-up visits. Exclusion Criteria: * Unable or unwilling to provide informed consent and assent. * Eye injury or surgery within twelve weeks immediately prior to enrollment. * Currently enrolled in an ophthalmic clinical trial. * Pregnant or lactating or expect to become pregnant during the trial (by self-report). * Evidence of systemic or ocular abnormality, infection or disease. * Use of medications that may affect the eye (including, but not limited to, corticosteroids and antimetabolites). * Anisometropia ≥ 2.00. * Subjects who have undergone corneal refractive surgery. * Use atropine or other anticholinergic drug within the past month. * Employees or immediate family members of employees of study sites or sponsor.