An optical system (single lens) is already entered by default.
Your system parameters must be entered in the various tables accessible by the "inputs" drop down menu. Read the support information provided through the related "about", "caution" and "tutorial" buttons.
Start by entering the number of surfaces of your system in this page or opt for quick entry from catalog components using the "inputs/quick entry" interface in which information at each step are provided ( button).
Analysis and optimization of your system are directly processed thanks to the various buttons of the drop down menus displayed on the right of the "calculate " label.
Save your system regularly in the "Save/upload" page.