Abstract:Visual detection is a technique for evaluating the results through visual judgment without relying on complex optical detection systems. It obtains results quickly based on signals, such as visible light, changes in air pressure, and migration distance, that can be directly observed by naked eyes, being widely used in the in vitro diagnostics industry. The CRISPR-Cas system has the potential to be used in the development of point of care testing (POCT) technologies due to the advantages of mild reaction conditions, no need for thermal cycling or other control measures, and a robust signal amplification capability. In recent years, the combination of visual detection and CRISPR-Cas has significantly reduced the need for laboratory infrastructures, precision instruments, and specialized personnel for nucleic acid detection. This has promoted the development of POCT technology and methods for nucleic acids. This article summarizes the signal output modes and characteristics of the visual detection of nucleic acid by CRISPR-Cas and discusses the issues in the application. Finally, its future clinical translation is envisioned with a view to informing the development of CRISPR-Cas visualization assays.