Since each time the glass is substituted during optimization the merit function value makes a discontinuous jump, glass substitution requires the use of global optimization algorithms such as Global Search or Hammer, instead of the damped least squared method (local optimization). 

The glasses selected for substitution are chosen from the current glass catalogs for the system, listed under System...General...Glass Catalog, which in this case is the Schott catalog. 

Open the OPD fan plot to note the performance of the system before optimization. The OPD scale is 0.5 waves.

Perform the Hammer optimization by clicking Tools...Optimization...Hammer Optimization in the main ZEMAX menu. Check the “Auto Update” option to see the changes in the Lens Data Editor and the OPD fan plot during optimization.

Click “Hammer” to optimize

You will see the glasses being substituted during optimization and see the changes in the OPD fan window.