R-32 with a low boiling point, high latent heat and a low GWP is promising to resplace R-134a and R-404A with high GWPs. Whereas the clinical potential in terms of cooling performance and laser attenuation is needed to be evaluated, and the complicated interaction mechanism between spray and lasers is urgent to be understood to optimize cooling parameters for clinicians. In this paper, the cooling performance and laser attenuation for R-134a, R-404A and R-32 are compared using the well-constructed transient CSC facility. Results demonstrate that three distinct stages of scattering by droplet, liquid film absorption and scattering by frost occurs in the variation of light transmittance. R-32 has the maximum surface heat flux (519.0 kW·m^-2), the shortest liquid film residence time (142 ms), and the least light attenuation under the irradiations of 755-nm and 1064-nm lasers owing to the low boiling point and large latent heat. The strong cooling capability, short liquid film residence time and small light attenuation of environment-friendly R-32 imply its good clinical application potential. But the clinical safety and feasibility of R-32 still requires the validation of clinical trials in patients, because of the absence of medical cryogens.