Like so much about love, the question of love at first sight can't be answered objectively. But I'll do my best to answer it here in the most helpful way. Is Your Mind Playing Tricks on You? 
Have you ever seen someone and instantly felt attracted to every part of them, including their personality (even though you haven't even talked to them yet)? You might be quick to call it love at first sight, but it's probably what psychologists call the attractiveness halo effect . When you see someone who looks great, your brain sometimes jumps to the conclusion that their personality must be great, too.

We all know that not everyone's looks and personalities match up. Some attractive people are total jerks, and some of the best people in the world aren't what you'd necessarily think of as hot. So the halo effect is really just an illusion. Your sudden feelings of love might go away as soon as you get to know the person better. 

Love: More than Just Looks 
Everyone's got a different take on what love is , but few people believe that's made out of stuff you can find just by looking at someone. Love (at least if you ask me) is made up of compromise, empathy and patience. You can't give or get those sorts of things at first sight. 

That doesn't mean that your initial feelings can't turn into love. When you first see someone, you might instantly know that you want to get close to them and learn about them. As your relationship progresses, those feelings might eventually grow into love. But is "love" really the word for your gut reaction? 

When Couples "Just Know" 
You might meet couples who say that when they saw each other for the first time, they "just knew." What did they really know? Probably that they liked how the other person looked and acted, and that they wanted to take things to the next step and get to know each other better. 

If they want to call it "love at first sight," that's okay by me. But keep in mind that there are lots of other couples who get the same feeling when they meet each other, and it ends badly or doesn't go anywhere at all. It's not the first glance that makes it love. It's the stuff that comes later - the commitment and caring that makes a relationship last. 

The Danger of Believing Too Strongly in Love at First Sight 
You might be wondering why I'm giving love at first sight such a bad rap. It's not that I don't think the idea is sweet, or that I don't love me some romantic movies. (My favorite love at first sight scene's gotta be this one from Romeo and Juliet .) 

But it's wrong to think that if you don't have intense feelings right away, it could never be love. Some of the best and strongest relationships started out in totally unromantic ways. 

More importantly, though, the halo effect can be dangerous. If you see someone hot and assume that what you feel is love, you'll overlook qualities in them that could end up hurting you. You might let them get away with abusive behavior because your heart has taken over your better judgment. 

So What's the Answer? 
Whether or not you want to believe in love at first sight is up to you. Just don't go out there expecting to find it and get upset when you don't. 

And when you meet someone you instantly swoon over, be aware that there's a whole lot about them you haven't seen yet - including some stuff that might not be so deserving of your love.