$\sigma^{tot}_{ee \gamma \gamma}$ at $e^+e^-$ colliders}

In this talk I briefly summarize different models for $\sigma^{tot}_{2 \gamma}$ ($e^+e^- \to \gamma \gamma \to$ hadrons) and contrast model predictions with the data. I will then discuss the capability of the future $e^+e^-$ and $\gamma \gamma$ colliders to distinguish between various models and end with an outlook for future work.