# Color Brightness Recognition of Extremely Severe Amblyopia Children in an Indoor Environment
## 1 Introduction  
According to the survey and estimate conducted by the World Health Organization in 2010, there are approximately 285 million visually impaired people worldwide, accounting for about 4.24% of the total global population. Among them, 39 million are blind, while 246 million individuals have impaired vision [1]. In China, there is a population of over 40 million individuals who are visually impaired, including 12 million children, with this figure continuing to rise [2]. Visual impairment encompasses blindness and low vision [3], which are classified into five levels: mild (0.5-0.8), moderate (0.3-0.5), severe (0.1-0.3), very severe (0.05-0.1), and complete blindness (below 0.05) [4]. Compared with sighted children, visually impaired children face challenges in visual acuity or field, either due to congenital or non-congenital factors. These challenges restrict their involvement in education, work, and social activities and seriously affect their quality of life as well as their physical and mental health [5; 6; 7]. It is important to note that many visually impaired children are not completely blind [8]. Instead, they have poor vision and heavily rely on color perception compared to others with normal vision [9]. Many studies have shown that color design can improve the visual recognition of visually impaired children, which plays an important role in their growth [10; 11]. Additionally, color design in indoor environments has an impact on their cognitive abilities, attention span, creativity, emotions, and personality development [12]. Special education schools catering to visually impaired children in China play a crucial role in providing fundamental education and serve as a cornerstone of special education [13]. Unfortunately, a solid foundation in design research within the architectural domain is conspicuously absent in these institutions [14; 15; 16]. Early studies focusedon examining the methodologies of interior and furniture design for various functional spaces, with a keen consideration of ergonomics for individuals with disabilities [14; 17; 18; 19]. Follow-up studies have underscored the significance of the environment for special groups, demonstrating that interventions in the built environment are instrumental in the developmental progress of children with disabilities [1; 6; 20; 21; 22]. Given the challenges faced by visually impaired individuals in spatial orientation [21] and the multifaceted role of color as a tool for identification, grouping, highlighting, warning, and interpretation within educational settings [23], the color design of school campuses plays a crucial role in the lives of visually impaired children [24; 25]. Many scholars have a misunderstanding regarding the visual capabilities of the visually impaired population, often conflating individuals with visual impairments with those who are completely blind, thereby assuming they have entirely lost their vision. As a result, early research predominantly focused on Braille, sensory compensation, and obstacle avoidance devices, with very limited attention given to the study of color. Over time, research specifically targeting individuals with low vision has gradually emerged, including studies on ocular devices and VR games, where color was used as a tool within other research contexts. However, these studies were primarily aimed at improving vision through instruments, and their conclusions were not specifically centered on color. We have identified the critical role of special education schools for children with visual impairments and noted a significant lack of research on the use of color in indoor environments for the visually impaired. We believe that indoor color can assist in visual recognition for this population, which serves as the foundational motivation for our study. There is a scarcity of research that connects the visually impaired population, indoor environments, and color.