I personally don't believe in love at first sight. It seems more of a fairy tale concept than anything truly real. Love is hard and takes effort, there are no shortcuts.
What some people may feel is love at first sight, is most likely just an intense physical attraction and nothing more. It's a nice thing to start with; to build off of, and I would say it's an important first step, but to confuse that with love is setting oneself up for failure.
Think about this: Can laying your gaze upon someone tell you what kind of goals she has? Can you see a person's personality? When at first your eyes meet, can you be sure he is not a chainsaw murderer?
I believe to find true love, one must abandon all Disneyesque absurdities and get to know the person over time, naturally. Be open to the possibility that they are flawed and need guidance (as do you) and only then, when you've stopped being an unrealistic ass, will you find what you desire.