I would normally respond that you need to recenter the view by focusing on something in the area you are working on by pressing 'f' but it appears you are already doing that
You can indeed change the OpenGL near and far values which are used for clipping but you really need to understand what they mean before you change them. There are many OpenGL resources where you should be able to find help on these values.
In the preferences file ac3dprefs8.txt (windows) or .ac3dprefs (Mac/Linux), look for these:
ogl_near 0.050000
ogl_far 1000000.000000