Older people with dementia manifest emotional and behavioral symptoms (EBS), such as emotion disorders, environmental adaptation problems, sleep disorders, limited mobility, etc. The indoor visual environment (IVE) in care and attention (C&A) homes may relieve or aggravate those EBS. To improve the IVE in C&A homes and satisfy the special requirements of older people with dementia, this study investigated the impact of the IVE in C&A homes on the EBS in older residents with mild to moderate dementia. The predesigned questionnaire survey was carried out among 100 participants with dementia living in C&A homes, and the interview was conducted with 12 staff members with different positions. An IVE–EBS model was established using various statistical analysis methods. The verified model demonstrated that the space, view out, window, furniture, door, and color significantly influenced the EBS in older people with dementia. Practical recommendations were proposed, including 1) relatively small space and unblocked vision for enhancing their confidence to move around; 2) a quiet view out with greenery, aesthetic scene, and broad perspective; 3) a window-to-floor ratio of the activity room higher than 1:4; 4) wooden furniture for a warm atmosphere; 5) dementia-friendly door wraps to improve the unique features of the doors; 6) a CCT of 2500K–3000K to promote older adults with dementia sleep well in the evening.