This is a rather debatable topic and I might as well receive mixed responses.
My definition of Love at first sight, is only on the basis of physical appearance. I guess good looking people are lucky? Or born lucky with good genes?
In my opinion, it's a merely an infatuation where one experiences a strong emotion towards someone, without really knowing them well. In other words, it's like falling in love with the idea of the person, not with their reality (living in an illusion fantasy world where you had glorified your love interest who is ideal and perfect) Apparently, by doing so you tend to ignore the obvious red flags - I know it's a bitter truth to accept the reality of incompatibility and probably he/she is just not into you.
There are quite a number of factors which makes a person believe that love at first sight does exist. One of it which most of us could relate is, romanticism - an artistic and intellectual movement which took place in Europe between the late eighteenth and mid-nineteenth centuries. The romantic movement emphasised on an emotional sensitivity and individual subjectivity. For the Romantics, imagination, rather than reason, was the most important creative faculty. Throughout the years, the influence of romanticism has engulfed in literature, arts and music where artists, poets and music crafted the feelings and emotions of falling love and heartbreaks in such a beautiful way , in which commonly made an individual adhere to a strong desire or craved to be in love. I wouldn't deny the fact that, it requires an amazing talent and creativity, and these artists are indeed the great minds.
Many of us are not aware ( I wasn't and learned it the hard way) we often misunderstand it as love but it might as well be limerance - defined as the emotional state of uncontrollable obsession and infatuation for a particular person, called the Limerent Object, coupled with a desire to obtain their emotional commitment and begin a relationship with them.
So, in simple words its basically the honeymoon phase. Where everything seems to be a bed of roses. On an average limerance lasts for 18 months to 3 years (which is quite a long time) and now how can one justify love at first sight as true love?
Because I believe love is a strong word, that builds naturally by witnessing the beautiful and ugly of an individual and taking a stand of not leaving the person no matter what.
Infatuation will fade, and it will fade quicker than you realize.
Therefore, I don't really believe in love at first sight.
As the process of getting to know each other in depth, you tend to realize, understand and accept each other's- fears, flaws, insecurities, strengths and weakness. Subsequently, you would soon realize the compatibility levels and feelings reciprocation.
In reality, that's how it eventually develops into true love.
Thank you for reading :)