You can open an IGES file in Autodesk Inventor LT (creating a file) or import an IGES file into an existing Autodesk Inventor LT part file.
When you use 
Open and select an IGES file, click Options to set import options. On the Import Options dialog box, specify the data to import and other conditions to be applied.
Choose the data to import by selecting Solids, Surface, Wires, Points, or any combination.
Composite features have the same behavior as Base Surface features, but they can also have multiple individual solid and surface bodies within them. While the composite can contain multiple bodies, you cannot work directly with the individual bodies. You can only interact with the composite as a whole.
If possible, multiple surfaces are stitched together into a single part. If edges do not match exactly, the surfaces are stitched into the smallest number of quilts possible.
Surfaces that cannot be stitched together remain in the Construction folder in the browser. Quilts are promoted to the part environment and are shown as surfaces in the browser. In the construction environment, you can analyze and repair surfaces that did not automatically stitch when they were imported.
Optionally, you can ignore the 308/408 subfigure (block) definitions and open all the data into a single part file. To do this, open a new part and click the Insert menu, and then click the Import option to import all the data into the new part doc.