Myopia is a leading cause of visual impairment worldwide, with prevalence rising rapidly among children. Growing evidence suggests that environmental and behavioral factors play a dominant role in ocular growth; however, current studies typically isolate single components of the visual environment, such as near work or light intensity, limiting investigators' understanding of how multiple visual stimuli interact within individuals over time. The retina is continuously exposed to a dynamic "visual diet," encompassing viewing distance, illuminance, spectral composition of light, and temporal viewing patterns, as well as associated visuomotor responses such as eye vergence and pupil dynamics. A critical barrier to myopia prevention is the lack of longitudinal, quantitative measurements that integrate these factors in real-world settings during childhood ocular development.

The long-term goal of this project is to prevent myopia onset and slow myopia progression through individualized, patient-centered monitoring and modification of the visual diet. The overall objective of this proposal is to longitudinally characterize visual diet and visuomotor behavior in children and to identify the most influential environmental and physiological factors driving myopia onset and progression. The investigators will conduct a 3-year longitudinal observational study enrolling 60 children aged 7-12 years, including myopic children and non-myopic children stratified by risk of myopia progression.

Visual stimulation plays a critical role in guiding eye growth through activity dependent mechanisms. To date, this visual stimulation or visual diet has been investigated by measuring isolated components including near work, light intensity, or wavelength across different individuals. However, this approach does not address how multiple components of the visual diet interact in the visual development of each individual child. Knowledge gap: There is an urgent need for longitudinal measurements from individual children that incorporate multiple components of the visual environment and visual function as the eye grows and develops. This proposal addresses this gap by measuring longitudinally children's visual diet using a combination of techniques that will record these multiple components with VEET (Visual Environment Evaluation Tool, Meta Reality labs), modern eye tracking, refraction, and biometry. The understanding of the interactions between the visual environment and visual function will allow us to develop more effective approaches for myopia prevention and control.

One major reason that visual diets remain under-investigated is the lack of appropriate technology. The investigators propose to use the novel VEET to measure spectral irradiance, illuminance, viewing distance, and head motion. In addition, the investigators propose to use modern wearable eye tracking to quantify visuomotor response during reading. The investigators' long-term goal is to prevent myopia onset and slow myopia progression in children through an individualized, patient-centered approach that monitors and modifies the visual diet. The specific objective of this proposal is to identify what individual features of the visual diet have the strongest impact on myopia development, and provide specific guidelines to monitor and modify them accordingly in an individualized manner.

Inclusion Criteria:

• Age: 7-12 years old (inclusive)
• Astigmatism of < 1.50D
• Stereopsis equal or better 100 seconds of arc
• Normal binocular functions.

In addition, for the Myopic group:

- Cycloplegic autorefraction (spherical equivalent, SEQ) between -0.50D and -6.00D, who are not currently pursuing nor intending to start myopia control at the time of enrollment.

For the non-myopic group:

- SEQ between plano and +2.50D.

Exclusion Criteria for both groups:

• History of refractive surgery or myopia control
• Binocular abnormalities
• Ocular and systemic pathologies
• Developmental delay
• Unable to wear the VEET at home for 8 days every 6 months for 3 years
• Pre-term birth (< 34 weeks of gestational age).

Participants will be selected from the Pediatric Clinic at the College and from the local community.