The early visual screening of children plays a critical role in promoting visual development, especially for those with visual impairments. Among various approaches, eye-tracking based visual assessment has emerged as a promising tool, particularly for infants, toddlers, and children with developmental disabilities who are unable to complete traditional vision tests. The object of this study is to design and investigate the effectiveness of using a deep learning based, individualized eye-tracking system to assess visual function, specifically visual acuity and visual field, in typical preschool children and infants under the age of three. This study aims to establish a reliable, noninvasive visual screening method that accommodates the diverse needs and abilities of young children.

The investigators will recruit a total of 1,300 participants across four key groups to support the development and validation of an individualized visual function screening system using eye-tracking technology:

1. 300 adults to establish a reference dataset for gaze estimation models
2. 300 typically developing preschool children aged 3 to 5 years
3. 400 typically developing children under the age of 3
4. 300 children with special needs, including those with developmental disabilities and visual impairments Data collection will take place over 15 to 22 months, depending on the group.

Inclusion Criteria:

• A. General Group 1. Inclusion Criteria

General adults:

1. Aged over 18 and under 70 years
2. Willing to undergo assessment and video recording using the "Deep Visual Tracking System"
3. Willing to sign the informed consent form

Typically developing preschool children aged 3 to 5:

1. Currently aged between 3 (inclusive) and 5 (inclusive) years
2. The primary caregiver agrees to allow the child to undergo assessment and video recording using the "Deep Visual Tracking System"

Children under 3 years old:

1. Currently under 3 years of age
2. The primary caregiver agrees to allow the child to undergo assessment and video recording using the "Deep Visual Tracking System"

2. Exclusion Criteria

General adults:

1. Presence of severe corneal disease or cataract that may interfere with data collection
2. Obvious abnormalities in eye or facial appearance, such as ptosis or facial trauma affecting facial structure

Typically developing preschool children aged 3 to 5:

1. Children with physical or mental disabilities
2. Children diagnosed with or suspected of having developmental delay
3. Children with obvious abnormalities in eye or facial appearance

Children under 3 years old:

(1) Children with physical or mental disabilities (2) Children diagnosed with or suspected of having developmental delay (3) Children with obvious abnormalities in eye or facial appearance

________________________________________ B. Special Needs Group

1. Inclusion Criteria (1) Children under the age of 12 with special needs, including physical, mental, or multiple disabilities (2) The primary caregiver agrees to allow the child to undergo assessment and video recording using the "Deep Visual Tracking System"
2. Exclusion Criteria (1) Children with refractive errors that are diagnosed by an ophthalmologist to significantly impair vision and are unable to wear corrective glasses during assessment (2) Children who are physiologically or emotionally unstable and unable to adapt and complete at least two assessment sessions

B. Special Needs Group

1. Inclusion Criteria (1) Children under the age of 12 with special needs, including physical, mental, or multiple disabilities (2) The primary caregiver agrees to allow the child to undergo assessment and video recording using the "Deep Visual Tracking System"

   Exclusion Criteria:

   • A. General Group

2. Exclusion Criteria

General adults:

1. Presence of severe corneal disease or cataract that may interfere with data collection
2. Obvious abnormalities in eye or facial appearance, such as ptosis or facial trauma affecting facial structure

Typically developing preschool children aged 3 to 5:

1. Children with physical or mental disabilities
2. Children diagnosed with or suspected of having developmental delay
3. Children with obvious abnormalities in eye or facial appearance

Children under 3 years old:

1. Children with physical or mental disabilities
2. Children diagnosed with or suspected of having developmental delay
3. Children with obvious abnormalities in eye or facial appearance

B. Special Needs Group 2. Exclusion Criteria

1. Children with refractive errors that are diagnosed by an ophthalmologist to significantly impair vision and are unable to wear corrective glasses during assessment
2. Children who are physiologically or emotionally unstable and unable to adapt and complete at least two assessment sessions

General adults, typically developing preschool children aged 3 to 5 and under 3 years old. Additionally, children with special needs, regardless of the underlying cause, including those with physical or mental disabilities or multiple disabilities, such as autism spectrum disorder, cerebral palsy, visual impairments, and developmental delays.