First of all, I don't drink. Ever (read: never in my life, ever). In other words, I can confirm with certainty that I have never donned the Beer Goggles. Don't get me wrong, I have my weaknesses, but the affinity for this hip ocular accessory is not my style. For this reason I feel I can objectively evaluate the meaning and origin of this man clause from the perspective of one that has never been tainted by this human frailty.
And now to the point. This clause probably goes without explanation. I don't know of anyone that does not know of the expression and meaning of Beer Goggles. It is a term of self-exoneration that immediately follows the aftermath of a moment of poor judgment. On the surface it may seem simple enough. You drink. Your eyesight is changed drastically along with your ability to reason. You become attracted to someone you would not otherwise be attracted. You do things with that person. When your buddies charge you with your crimes, you acquit yourself by alluding to your sense of fashion - specifically your taste for vision-altering eyewear. You and your friends get a kick out of it. The end.
However, I believe there is more to it. I see serious issues with blaming your mistakes on what you are CHOOSING to wear. As an example, who, in his right mind will approach someone they are attracted to while wearing Crocs? Who after being shunned by everyone at the pool because of his bacteria-resistant footwear can rightly say, "they rejected me because I was wearing my Crocs!" (clause coming soon, I'm sure of it) and expect any sympathy from his jury of peers? Of course they rejected you because of your Crocs, moron! All that is good on this green earth screams in unison in rejection of your choice in footwear and value as a human! The point is, YOU put on the Crocs and YOU chose to wear them at the all-important moment of breaking the ice.
To continue - if you wear Crocs, fine by me. Well at least fine by me after I finish verbally and/or physically abusing you. That's your choice. Blame a one night stand or similar event on beer goggles - although you may think the other effects of alcohol were worth the risk and justify your actions - and you will get no sympathy from me. It's a choice. A bad one. Period. Don't put them on. And if a good friend warns you that you're wearing them again, even though you can't feel the slightest sensation anywhere in the region of your upper cranium, trust him.
That is not all. Our English language has been negatively effected by the goggles. Idiomatic expressions like, "Look what the cat dragged in!", "Walk of shame", and even "Don't tase me bro!", and "I made out with you?", are literary and linguistic bastard children...errrrr...offspring of this recurring situation since the beginning of mankind.
There is hope. You are not alone. There are those that have gone before you throughout the centuries and survived the punishment and ridicule, and actually reproduced with attractive mates. As a final historical observation, I think it can be argued that the beer goggles existed before regular goggles. Whether you believe me or not, clause #37 is eternal.