I don't really have the problem of not being able to hold my alchohol. I don't drink very often, once a month, but when I do I usually drink about a pint maybe pint and a half of bourbon. I haven't had any problems with vision, balance, or memory. When I was in college it wasn't uncommon to drink a fith on a weekend night and a liter or two of Guiness each night (I know this was stupid), so maybe my body has just built up a tolerance over the years.

Basically what I'm trying to say is I really think that it is how an individuals body handles alchohol in general, but I could be wrong.