Not exactly 'eye gouging' but...
To my way of thinking, the eyes are a valid target, but not a primary target in most cases. As primates who are historically absolutely dependent upon vision for survival, it is deeply ingrained in our basic instincts to protect our eyes. Most rapid hand movement towards the eyes, or even light contact to the eyes, causes an instant and almost always involuntary reaction. The head jerks back, the hands come up, the eyes close, etc.
This creates opportunities to strike exposed areas that can end a fight. If you happen, in the course of self-defense, to actually disrupt the attacker's vision, all the better.
To me, self-defense requires rapid removal of the ability of the attacker to continue to attack. This can be accomplished in many ways. Creating distance, damaging attacking limbs, removing the ability of the attacker to pursue, and so on. If they cannot see, they cannot fight. Moreover, they won't WANT to fight, they will want to retreat and protect their eyes. Even someone who is very intoxicated or drugged is still hard-wired from primal times to protect their eyes.
So for me, an eye strike, even an incomplete strike, is a very good idea if the opportunity presents itself in a self-defense scenario. But I would not depend upon it to incapacitate or end the fight by itself. If it does, great. If it does not, an instant followup technique using the moment of distraction is the way to go.
Actual gouging of the eyes? I see that in close quarters, perhaps. If both parties are on the ground, maybe, or circumstances such as those. As valid as a gonad grab-and-twist. Although honestly, if you've ever gotten your thumb into your own eye accidentally, you know it's a dull pain, not the instant, sharp, pain of grabbing a handful of skin under the bicep and just squeezing the crap out of it, or the inside of the thigh near the groin with the same grab (not to mention the testicles, always a popular target). That kind of pain gets attention in all but the very drunk or drugged. I suspect I'd still go for an eye poke rather than an eye gouge, though. A fast stiff-fingered jab into the eyes, and prepare for an instant secondary attack based on the reaction to the eye poke.
Just my thoughts as a student.