I think it's vice versa: not computer geeks end up wearing glasses, but boys with glasses will become geeks.
The good looking guys spend lot of their time in fitness centers (some of them becoming athletes), dating girls (some of them becoming playboys), or just wasting their time (most of them becoming managers).
The guys with glasses are shy, they think they are ugly, thus they need a mask for their social life. Thus they are hiding behind a computer. And some of them will become computer geeks.
There is an exception to this rule: Austin Powers...