Hi Jenet! It may be a fine distiction as Dr Bill says, and I can’t speak for USen’s, but I think you are right from a Brit’s perspective.

It seems to me that the difference lies between the observational failure of “I do not see it” (which implies that the possibility exists) and the constitutional failure of “I cannot see it” (which implies that you will never be able to do so). Either way is frequently used in either way, however, with just the context making the meaning clear.