A light ray traveling in air strikes a spherical water droplet at an angle of incidence \(\theta_1\) relative to the surface normal. Upon entering the droplet, the ray refracts at an angle \(\theta_2\) relative to the normal, travels through the droplet, undergoes a single internal reflection at the back surface, and refracts back out into the air. In terms of \(\theta_1\) and \(\theta_2\), what is the total angle of deviation \(\theta_{\text{dev}}\), defined as the total angle through which the ray has turned after exiting the droplet?