The thermal stresses based upon the temperature history have been derived, so as to calculate the thermal shock index (TSI), which represent the new boarder line of safety for the over all clinical parameters. The discussion started with the mathematical one dimensional formulation and extended then to the three dimensional solution using the Finite Element Method (FEM) presented by the commercial package ANSYS! Experimental works using simulated PMMA disc have been done to compare results. Collecting practical data for hundreds of patient and fed them back to Neural Network to train and validate this network so as to build intelligent system of decision, adding more conformity to the clinical pre investigations. Also, the thermal camera used here to check the temperature contour distribution during the surgery. The present Book, Discussed the temperature distribution upon the corneal surface during the laser eye surgery.