You're not gonna see the difference unless the rest of the camera you get is using equaly high quality components. Most cameras produce good quality images unless you get a really cheapo.
I'm not totally sure about this but I've heard that most sony cameras that bear the carl-zeiss logo, do not actually have a carl-zeiss lens, but one built to carl-zeiss spec by someone else. I know canon and kyocera make lenses for sony, but I'm pretty certain canon don't make lenses to other companies specifications.
You shouldn't need to worry about this unless you go for something high end. True, with the tiny lenses on the compact cameras nowadays you can get some poor dark images. But thats not a problem if you stick to a good brand like canon, nikon, olympus etc. Oh yeah, fuji, sony etc. ;-)
<b><font color=red>"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."</font color=red><font color=blue> - Benjamin Franklin</font color=blue></b>
Optics to a certain extent does in some way effect the camera resolution. A camera with an excellent optics that has a poorly made CCD is worthless, also a camera with a fairly good CCD with bad lens is also not really a best buy. Analog capture affect the final digital image because the Lens works the same way on both film and digital cameras, but instead of having the image transferred onto film, it is picked up by the CCD sensor. I would personally get a camera with a fairly good lens, easily done by buying a camera from bigger companies (i.e. canon, olympus, nikon, etc.) However, I would personally not pay a lot of money for the carl-zeiss lens, even though their better. When buying a digicam, look at the pictures rather than what lens they use.